ASTM E1367-03(2023)-用河口和海洋无脊椎动物测量沉积物相关污染物毒性的标准试验方法-国家数字标准馆

现行 ASTM E1367-03(2023)

到馆提醒

收藏跟踪

购买正版

Standard Test Method for Measuring the Toxicity of Sediment-Associated Contaminants with Estuarine and Marine Invertebrates 用河口和海洋无脊椎动物测量沉积物相关污染物毒性的标准试验方法

发布日期： 2023-01-01

1.1
本测试方法涵盖了在实验室中测试河口或海洋生物的程序，以评估与整个沉积物相关的污染物的毒性。沉积物可以从现场收集，也可以在实验室中掺入化合物。一般指导见第节
1 –
15
用于对河口或海洋片脚类进行沉积物毒性测试。用河口或海洋片脚类进行10天沉积物毒性试验的具体指南概述于
附件A1
和进行28天沉积物毒性试验的具体指南
羽毛细针介
概述于
附件A2
.
1.2
描述了在10天的实验室暴露中测试河口或海洋片脚类甲壳类动物的程序，以评估与整个沉积物相关的污染物的毒性(
附件A1
; 美国环保局1994a
(
1.
)
). 沉积物可以从现场收集，也可以在实验室中掺入化合物。概述了在美国沿海水域发现的四种河口或海洋沉积物洞穴片脚类动物的毒性方法。物种是
阿布迪塔Ampelisca abdita
，一种海洋物种，栖息于大西洋海岸、墨西哥湾和旧金山湾的海洋和中盐部分；
河口始haustorius
，一种太平洋沿岸河口物种；
羽毛细针介
，一种大西洋沿岸河口物种；和
阿氏Rhepoxynius abronius阿氏Rheoxynius
，一种太平洋沿岸海洋物种。一般来说，所描述的方法可以应用于所有四种物种，尽管驯化程序和一些测试条件（即温度和盐度）将是物种-
具体（章节
12
和
附件A1
). 毒性试验在1L玻璃室内进行，玻璃室内装有175 mL沉积物和775 mL上层海水。暴露是静态的（也就是说，水不会更新），并且在10天的暴露期内不给动物喂食。毒性测试的终点是存活，重新埋葬存活的片脚类动物作为一种额外的测量方法，可以用作一些测试物种的终点（
阿布罗尼乌斯乳杆菌
和
E.河口
). 为该试验制定的性能标准包括阴性对照处理中片脚类动物的平均存活率必须大于或等于90 %. 描述了用于孔隙水盐度大于0的沉积物的程序
哦
/
面向对象
至完全海运。
1.3
还描述了一种用片脚类测定与整个沉积物相关的污染物的慢性毒性的程序
羽毛细针介
实验室暴露(
附件A2
; USEPA-USACE 2001年
(
2.
)
). 毒性试验在1L玻璃室内进行28天，其中含有175mL沉积物和约775mL上层水。试验温度为25°±2 °C，建议上覆水盐度为5
哦
/
面向对象
± 2
哦
/
面向对象
（对于孔隙水为1的试验沉积物
哦
/
面向对象
至10
哦
/
面向对象
)或20
哦
/
面向对象
± 2
哦
/
面向对象
（适用于孔隙水>10的试验沉积物
哦
/
面向对象
). 400毫升的上层水每周更新三次，在这三次中，测试生物被喂食。毒性测试的终点是片脚类的生存、生长和繁殖。
为该试验制定的性能标准包括阴性对照处理中片脚类动物的平均存活率必须大于或等于80 % 并且在阴性对照处理的所有重复中必须有可测量的生长和繁殖。本试验适用于从少卤到全海洋环境的沉积物，淤泥含量大于5 % 粘土含量小于85 %.
1.4
盐度为5或20
哦
/
面向对象
建议用于28-d测试的常规应用
羽毛乳杆菌
(
附件A2
; USEPA-USACE 2001年
(
2.
)
)盐度为20
哦
/
面向对象
建议用于10-d测试的常规应用
E.河口
或
羽毛乳杆菌
(
附件A1
). 然而，用这两种物种进行测试时，上覆水的盐度可以调整到感兴趣的特定盐度（例如，代表感兴趣地点的盐度，或者研究的目的可能是评估盐度对沉积物中化学物质生物利用度的影响）。
更重要的是，测试的盐度必须在测试生物体的耐受范围内（如
附件A1
和
附件A2
). 如果使用与中所述程序不同的程序进行测试
1.3
或在
表A1.1
（例如，不同的盐度、光照、温度、喂养条件），需要额外的测试来确定结果的可比性(
1.10
). 如果不需要在研究之间进行比较，那么可以仅在感兴趣沉积物的选定盐度下进行测试。
1.5
本标准的未来修订可能包括额外的附件，说明对其他河口或海洋无脊椎动物组进行的全沉积物毒性试验（例如，指南中提供的信息
第1611页
关于用多毛类进行的沉积物测试，可作为本标准未来修订的附件）。本标准的未来版本还可能包括在沉积物较少的较小室内进行毒性试验的方法（Ho等人，2000
(
3.
)
，Ferretti等人，2002年
(
4.
)
).
1.6
本标准中概述的程序主要基于美国环境保护局（1994年a
(
1.
)
)，USEPA-USACE（2001年
(
2.
)
)，测试方法
第1706页
、和指南
第1391页
,
1525欧元
,
第1688页
，加拿大环境部（1992年
(
5.
)
)，DeWitt等人（1992a
(
6.
)
; 1997年a
(
7.
)
)，Emery等人（1997年
(
8.
)
)，以及Emery和Moore（1996年
(
9
)
)，Swartz等人（1985年
(
10
)
)，DeWitt等人（1989年
(
11
)
)，斯科特和雷德蒙（1989年
(
12
)
)和Schlekat等人。
(1992
(
13
)
).
1.7
目前正在进行其他沉积物毒性研究和方法开发，以
(1)
完善沉积物加标程序，
(2)
完善沉积物稀释程序，
(3)
完善沉积物毒性鉴定评估（TIE）程序，
(4)
提供额外数据，以确认对底栖生物自然种群的实验室测试中的反应（即实地验证研究），以及
(5)
评估使用河口或海洋片脚类动物进行的10天和28天毒性试验中测得的终点的相对灵敏度。这些信息将在本标准的未来版本中进行描述。
1.8
尽管标准程序在
附件A2
进行慢性沉积物试验的标准
羽毛乳杆菌
，对某些问题的进一步调查可能有助于解释测试结果。其中一些问题包括进一步调查，以评估致命和亚致命终点对沉积物中掺入的各种化学品以及现场污染梯度对沉积物中化学品混合物的相对毒理学敏感性（美国环保局-美国环境保护局，2001年
(
2.
)
). 需要进一步的研究来评估致命和亚致命终点的能力，以估计底栖无脊椎动物种群和群落对受污染沉积物的反应。还需要进行研究，将毒性试验终点与现场验证的人群模型联系起来
羽毛乳杆菌
这将产生对人口的估计-
两栖动物对测试沉积物的水平响应，从而为实验室毒性测试提供额外的生态相关解释指导。
1.9
本标准概述了评估沉积物毒性的具体试验方法
阿卜迪塔
,
E.河口
,
羽毛乳杆菌
和
阿布罗尼乌斯乳杆菌
虽然本标准中描述了标准程序，但对某些问题的进一步调查可能有助于解释测试结果。其中一些问题包括航运对生物体敏感性的影响、生物体健康的额外性能标准、同一测试物种的不同种群的敏感性，以及对天然底栖生物种群的实验室测试反应的确认。
1.10
本标准中描述的一般程序可能有助于对其他河口或海洋生物进行测试（例如，
Corophium属。
,
日本大花介
,
dytiscus鳞翅目
,
本笃Streblospio
)，尽管可能需要进行修改。使用与测试方法中描述的程序不同的程序进行的测试结果，即使是相同物种的测试，也可能不具有可比性，使用这些不同的程序可能会改变生物利用度。对使用这些程序的修改版本获得的结果进行比较，可能会提供有关用水生生物进行沉积物测试的新概念和程序的有用信息。如果使用与本试验方法中所述程序不同的程序进行试验，则需要进行额外的试验以确定结果的可比性。
本试验方法中描述的一般程序可能有助于对其他水生生物进行试验；然而，可能需要进行修改。
1.11
毒性测试生物的选择:
1.11.1
测试生物体的选择对测试的相关性、成功性和解释有着重要影响。此外，没有一种生物最适合所有沉积物。在选择本标准中描述的测试生物体时，考虑了以下标准(
表1
和指南
1525欧元
). 理想情况下，测试生物体应:
(1)
具有毒理学数据库，该数据库表明对沉积物中一系列感兴趣的污染物的相对敏感性，
(2)
有一个数据库，用于对程序进行实验室间比较（例如，圆形-
robin研究），
(3)
与沉积物直接接触，
(4)
易于从培养物或通过田间收集获得，
(5)
易于在实验室中维护，
(6)
易于识别，
(7)
具有重要的生态或经济意义，
(8)
具有广泛的地理分布，是被评估地点的本土生物（无论是现在的还是历史的），或者具有与关注的生物相似的生态位（例如，与本土生物相似的喂养协会或行为），
(9)
能够承受广泛的沉积物物理化学特性（例如粒度），以及
(10)
与选定的暴露方法和终点兼容（指南
1525欧元
). 利用选定生物体的方法也应
(11)
同行评审（例如，期刊文章）和
(12)
与海底生物自然种群的反应相证实。
ATL=大西洋海岸，PAC=太平洋海岸，GOM=墨西哥湾
1.11.2
在这些标准中(
表1
)，一个数据库，表明对污染物的相对敏感性、与沉积物的接触、实验室培养的方便性或现场收集的可用性、实验室处理的方便性、对不同沉积物物理化学特性的耐受性，以及对天然底栖生物群的反应的确认，是选择的主要标准
阿卜迪塔
,
E.河口
,
羽毛乳杆菌
和
阿布罗尼乌斯乳杆菌
适用于本标准的当前版本，用于10天沉积物试验(
附件A1
). 这种方法选择的物种与沉积物密切相关，因为它们的管道-
居住或自由洞穴，以及吞噬沉积物的自然。两栖类动物已被广泛用于测试海洋、河口和淡水沉积物的毒性（Swartz等人，1985年
(
10
)
; DeWitt等人，1989年
(
11
)
; 斯科特和雷德蒙，1989年
(
12
)
; DeWitt等人，1992a
(
6.
)
; Schlekat等人，1992年
(
13
)
). 本标准测试物种的选择遵循了沉积物毒理学领域专家的共识，他们参加了题为“淡水和海洋沉积物的测试问题”的研讨会。该研讨会由美国环保局水资源办公室、科学技术办公室和研发办公室赞助，于1992年9月16日至18日在华盛顿特区特区举行（美国环保局，1992
(
15
)
).
在研讨会上讨论的候选物种中，
阿卜迪塔
,
E.河口
,
羽毛乳杆菌
和
阿布罗尼乌斯乳杆菌
最佳地满足了选择标准，并提出了大西洋（河口
羽毛乳杆菌
和海军陆战队
阿卜迪塔
)和太平洋（河口
E.河口
和海军陆战队
阿布罗尼乌斯乳杆菌
)海岸。
阿布迪塔Ampelisca abdita
它也是墨西哥湾和旧金山湾部分地区的本土物种。许多其他可能适合沉积物测试的生物现在不符合这些选择标准，因为很少重视制定海底生物的标准化测试程序。例如第五物种，
日本大花介
没有被选中，因为研讨会参与者认为该物种的使用范围不够广泛，不足以保证该方法的标准化。加拿大环境部（1992年
(
5.
)
)建议使用以下两足类物种进行沉积物毒性测试:
弗吉尼亚两栖孔虫
,
卷尾藻
,
华盛顿始豪斯介
,
西溪狐
和
扁细针介
。一个与可用于
阿卜迪塔
,
E.河口
,
羽毛乳杆菌
和
阿布罗尼乌斯乳杆菌
必须进行开发，以便将这些生物和其他生物纳入本标准的未来版本。
1.11.3
用于选择的主要标准
羽毛乳杆菌
对沉积物的长期测试是，该物种在美国东海岸河口的寡盐和中盐区都有发现，并且能够耐受广泛的沉积物粒度分布（美国环境保护局-
美国标准时间2001
(
2.
)
附件
附件A2
). 该物种很容易在实验室中培养，并且具有相对较短的世代时间（即，在23 °C，DeWitt等人，1992a
(
6.
)
)这使得该物种能够适应长期测试（第
12
).
1.11.4
在选择用于测试方法开发的特定物种时，一个重要的考虑因素是存在关于生物体对单一化学品和复杂混合物的相对敏感性的信息。几项研究评估了
阿卜迪塔
,
E.河口
,
羽毛乳杆菌
或
阿布罗尼乌斯乳杆菌
，或者相对于彼此，或者相对于其他通常测试的河口或海洋物种。例如，将海洋片脚类的敏感性与用于制定盐水质量标准的其他物种进行了比较。
七个两栖动物属，包括
阿布迪塔Ampelisca abdita
和
阿氏Rhepoxynius abronius阿氏Rheoxynius
，是用于制定12种化学品盐水质量标准的测试物种之一。将12种化学品中每一种的4天纯水试验的急性两栖动物毒性数据与
(1)
所有其他物种，
(2)
其他底栖物种，以及
(3)
其他臭名昭著的物种。两栖类动物在每次比较中通常具有中等灵敏度。在所有测试物种中，片脚类的平均百分位数为57 %; 在所有底栖物种中，56 %; 在所有臭名昭著的物种中，54 %. 因此，相对于所有物种、底栖物种，甚至臭名昭著的物种，片脚类动物并不是唯一敏感的（美国环境保护局1994a
(
1.
)
). 可能需要进行额外的研究，以开发使用始终比片脚类更敏感的物种的测试，从而为不太敏感的群体提供保护。
1.11.5
Williams等人（1986年
(
16
)
)比较了
阿布罗尼乌斯乳杆菌
10天全沉积物试验，牡蛎胚胎(
巨型螃蟹
)48小时异常试验，细菌(
鱼弧菌
)1小时发光抑制试验（即Microtox
2.
试验）对从华盛顿州开工湾46个受污染地点收集的沉积物进行处理。
阿氏Rhepoxynius abronius阿氏Rheoxynius
暴露于整个沉积物中，而牡蛎和细菌测试分别用沉积物洗脱液和提取物进行。Microtox公司
2.
是最敏感的测试，有63 % 引起发光显著抑制的位点。显著的死亡率
阿布罗尼乌斯乳杆菌
在40例中观察到 % 试验沉积物中，35只牡蛎出现异常 % 沉积物洗脱物。
在41中观察到完全一致（即，在所有三项测试中都是有毒或无毒的沉积物） % 沉积物的。其他地点缺乏一致性的可能原因包括测试生物之间敏感性的种间差异、与测试沉积物相关的污染物类型的异质性，以及每次毒性测试固有的暴露途径的差异。这些结果强调了在进行沉积物评估时使用多种分析的重要性。
1.11.6
几项研究比较了四种片脚类组合对沉积物污染物的敏感性。例如，在
阿卜迪塔
和
阿布罗尼乌斯乳杆菌
之间
E.河口
和
阿布罗尼乌斯乳杆菌
，以及介于
阿卜迪塔
和
羽毛乳杆菌
。在
E.河口
和
羽毛乳杆菌
，没有比较的示例
羽毛乳杆菌
和
阿布罗尼乌斯乳杆菌
在每个物种组合中，从比较到比较的相对敏感性有一些重叠，这似乎表明所有四个物种对受污染沉积物的相对敏感性都在相同的范围内。
1.11.6.1
Word等人（1989年
(
17
)
)比较了
阿卜迪塔
和
阿布罗尼乌斯乳杆菌
在一系列实验中对受污染的沉积物进行处理。这两个物种都在15岁时进行了测试 °C。实验被设计为比较生物体的反应，而不是提供方法的灵敏度的比较（即，
阿布迪塔Ampelisca abdita
通常在20岁时进行测试 °C）。从加利福尼亚州奥克兰港收集的沉积物被用于比较。在一次比较中测试了26种沉积物，而在另一次比较则测试了5种。使用Kruskal-Wallace秩和检验对两个实验的结果进行分析表明
阿布罗尼乌斯乳杆菌
对沉积物表现出比
阿卜迪塔
在15 °C。Long和Buchman（1989年
(
18
)
)还比较了
阿卜迪塔
和
阿布罗尼乌斯乳杆菌
来自加利福尼亚州奥克兰港的沉积物。他们还确定
阿卜迪塔
灵敏度低于
阿布罗尼乌斯乳杆菌
，但他们也表明
阿卜迪塔
对沉积物粒度因素的敏感性低于
阿布罗尼乌斯乳杆菌
.
1.11.6.2
DeWitt等人（1989年
(
11
)
)比较了
E.河口
和
阿布罗尼乌斯乳杆菌
在10天的测试中，添加了荧蒽的沉积物和从华盛顿州普吉特湾工业水道现场收集的沉积物，以及水性镉（CdCl
2.
)在4天的纯水测试中。的灵敏度
E.河口
从两倍（到掺入的加标沉积物）到七倍（到一个普吉特湾，华盛顿州，沉积物）的灵敏度比
阿布罗尼乌斯乳杆菌
在沉积物测试中，对CdCl的敏感性降低了十倍
2.
只在水中测试。Pastorok和Becker（1990）的研究结果支持了这些结果
(
19
)
)谁发现
E.河口
和
阿布罗尼乌斯乳杆菌
通常彼此相当，并且两者都比
齿脊牛膝
（存活和生物量终点），
普通潘诺普
（存续），以及
偏心Dendraster
（生存）。
1.11.6.3
羽毛细针介
和淡水两栖动物一样敏感
阿兹特克海勒拉
当后者适应寡卤盐盐度时，人为产生的沉积物污染梯度（即6
哦
/
面向对象
; McGee等人，1993年
(
20
)
). DeWitt等人（1992年b
(
21
)
)比较了
羽毛乳杆菌
以及从马里兰州巴尔的摩港收集的其他三种片脚类、两种软体动物和一种多毛类到高度污染的沉积物，这些沉积物被干净的沉积物连续稀释。
羽毛细针介
比片脚类动物更敏感
阿兹特克海勒拉
和
dytiscus鳞翅目
并表现出与
E.河口
Schlekat等人（1995年
(
22
)
)描述10天试验的实验室间比较结果
阿卜迪塔
,
羽毛乳杆菌
和
E.河口
使用从康涅狄格州黑石港收集的沉积物稀释液。在沉积物毒性的排名以及区分有毒和无毒沉积物的能力方面，物种和实验室之间达成了强有力的一致。
1.11.6.4
Hartwell等人（2000年
(
23
)
)评估了
羽毛细针介
（10天生存或生长）对两栖动物的反应
dytiscus鳞翅目
（10天生存或生长），多毛类
本笃Streblospio
（10天存活或生长）和生菜发芽（3天暴露的莴苣），并观察到
羽毛乳杆菌
与任一L的反应相比相对不敏感。
dytiscus或S.benedicti暴露于4种金属浓度升高的沉积物中。
1.11.6.5
氨是海洋沉积物中的一种天然化合物，是有机碎屑降解的结果。试验沉积物中的间质氨浓度范围从<1 mg/L到超过400 mg/L（Word等人，1997
(
24
)
). 一些底栖动物对浓度约为20 mg/L的氨表现出毒性（Kohn等人，1994年
(
25
)
). 基于纯水和氨水加标沉积物实验，已经为
羽毛乳杆菌
慢性测试。较小（较年轻）的个体比较大（较年长）的个体对氨更敏感（DeWitt等人，1997a
(
7.
)
b
(
26
). 28天的测试结果表明，新生儿可以在短时间内耐受非常高水平的孔隙水氨（总氨>300 mg/L），没有明显的长期影响（Moore等人，1997
(
27
)
). 这并不奇怪
羽毛乳杆菌
对氨具有很高的耐受性，因为这些片脚类通常存在于富含有机物的沉积物中，在这些沉积物中，成岩作用会导致孔隙水氨浓度升高。对氨不敏感
羽毛乳杆菌
不应被解释为
羽毛乳杆菌
沉积物对其他关注化学品的毒性试验。
1.11.7
在单一化学测试中，所有四种物种同时暴露在水中的比较数据有限。
现有的研究普遍表明，没有一个物种始终是最敏感的。
1.11.7.1
四种两栖动物对氨的相对敏感性是在十天无水毒性试验中确定的，以帮助解释存在这种毒物的沉积物的试验结果（美国环保局1994a
(
1.
)
). 这些试验是静态暴露，通常在与标准10d沉积物试验类似的条件下（例如盐度、光周期）进行。与标准条件的偏差包括没有沉积物和测试温度为20 °C用于
羽毛乳杆菌
，而不是25 °C，如本标准所述。所有四个物种对总氨的敏感性都随着pH值的增加而增加。
秩敏感性为
阿布罗尼乌斯乳杆菌
=
阿卜迪塔
>
E.河口
>
羽毛乳杆菌
Kohn等人的一项类似研究（1994年
(
25
)
)显示出相似但略有不同的对氨的相对灵敏度
阿卜迪塔
>
阿布罗尼乌斯乳杆菌
=
羽毛乳杆菌
>
E.河口
.
1.11.7.2
氯化镉是所有四种物种在4天暴露中常见的参考毒物。DeWitt等人（1992年a
(
6.
)
)将秩灵敏度报告为
阿布罗尼乌斯乳杆菌
>
阿卜迪塔
>
羽毛乳杆菌
>
E.河口
在15的普通温度和盐度下 °C和28
哦
/
面向对象
在特定物种的温度和盐度下进行的一系列为期4天的镉暴露显示出以下等级敏感性:
阿卜迪塔
=
羽毛乳杆菌
=
阿布罗尼乌斯乳杆菌
>
E.河口
（美国环保局1994a
(
1.
)
).
1.11.7.3
污染物之间的相对物种敏感性经常变化；因此，可能需要一系列包括代表不同营养水平的生物在内的测试来评估沉积物质量（Craig，1984
(
28
)
; Williams等人，1986年
(
16
)
; Long等人，1990年
(
29
)
; Ingersoll等人，1990年
(
30
)
; 伯顿和英格索尔，1994年
(
31
)
). 例如，Reish（1988
(
32
)
)报告了六种金属（砷、镉、铬、铜、汞和锌）对甲壳类动物、多毛类、pelecypods和鱼类的相对毒性，并得出结论，没有一个物种或一组受试生物对所有金属最敏感。
1.11.8
生物体的敏感性与暴露途径和对污染物的生物化学反应有关。
沉积物生物可以从三个主要来源接受暴露:间隙水、沉积物颗粒和上层水。食物类型、进食率、同化效率和清除率将控制沉积物中污染物的剂量。底栖无脊椎动物经常选择性地消耗不同粒度的颗粒（Harkey等人，1994
(
33
)
)或者具有较高有机碳浓度的颗粒，其可能具有较高污染物浓度。以aufwuchs和碎屑为食的放牧者和其他采集者的大部分身体负担可能直接来自附着在沉积物上的物质或实际的沉积物摄入。在一些片脚类动物中（Landrum，1989
(
34
)
)和蛤蜊（Boese等人，1990年
(
35
)
)对于某些疏水性化合物，通过肠道的摄取可能超过通过鳃的摄取。与沉积物直接接触的生物体也可能通过直接吸附到体壁或通过被膜吸收而积累污染物（Knezovich等人，1987
(
36
)
).
1.11.9
尽管估计动物从沉积物中接受的剂量可能很复杂，但沉积物中许多污染物（如Kepone®、荧蒽、有机氯和金属）的毒性和生物累积性与这些化学物质在间隙水中的浓度或非离子有机化学物的浓度有关，有机碳标准化基础上沉积物中的浓度（Di-Toro等人，1990年
(
37
)
; Di-Toro等人，1991年
(
38
)
). 整个沉积物和间隙水暴露途径的相对重要性取决于试验生物体和特定污染物（Knezovich等人，1987
(
36
)
). 由于底栖生物群落包含多种多样的生物，许多暴露途径的组合可能很重要。因此，测试生物的行为和进食习惯会影响其从沉积物中积累污染物的能力，在选择用于沉积物测试的测试生物时应予以考虑。
1.11.10
使用
阿卜迪塔
,
E.河口
,
阿布罗尼乌斯乳杆菌
和
羽毛乳杆菌
实验室毒性研究已通过海底生物自然种群的现场验证（Swartz等人，1994
(
39
)
和Anderson等人2001
(
14
)
对于
E.河口
，Swartz等人，1982年
(
40
)
和Anderson等人2001
(
14
)
对于
阿布罗尼乌斯乳杆菌
，McGee等人，1999年
(
41
)
以及McGee和Fisher，1999年
(
42
)
对于
羽毛乳杆菌
).
1.11.10.1
美国环保局研究与发展办公室的环境监测和评估项目的数据被检查，以评估
阿布迪塔Ampelisca abdita
在沉积物毒性测试中，以及在野外样品中存在片脚类动物，特别是两性孢子虫。在弗吉尼亚省（马萨诸塞州科德角至弗吉尼亚州亨利角）进行的两年采样中，有200多个沉积物样本可用于比较
阿卜迪塔
底栖生物群落计数毒性试验中的存活率。
尽管该属的物种是这些样本中出现频率较高的分类群之一，但在展出的站点中完全没有双孢子虫
阿卜迪塔
试验存活率<60 % 在对照样品中。此外，在两足类测试存活率在60至80之间的站点中，发现了密度非常低的ampelicids % （美国环保局1994a
(
1.
)
). 这些数据表明，对该物种的测试可以预测自然条件下污染物对敏感物种的影响。
1.11.10.2
Swartz等人（1982年
(
40
)
)比较灵敏度
阿布罗尼乌斯乳杆菌
从华盛顿州开工湾的现场收集的沉积物，到每个现场的底栖生物群落结构。死亡人数
阿布罗尼乌斯乳杆菌
与片脚类密度呈负相关，并且在污染最严重的地区普遍不存在光头类片脚类。
1.11.10.3
在10天毒性试验中，沉积物对片脚类的毒性、现场污染和底栖片脚类现场丰度沿着滴滴涕的沉积物污染梯度进行了检查（Swartz等人，1994
(
39
)
). 的存续
E.河口
和
阿布罗尼乌斯乳杆菌
实验室毒性测试与野外片脚类的丰度以及
阿兹特克人
，与滴滴涕浓度呈负相关。在实验室研究中，10天沉积物毒性的阈值约为300微克滴滴涕（+代谢物）/克有机碳。田间片脚类丰度的阈值约为每克有机碳100微克滴滴涕（+代谢物）。因此，毒性、污染和生物学之间的相关性表明，急性10-
d沉积物毒性测试可以提供现场生物不良沉积物污染的可靠证据。
1.11.10.4
作为马里兰州巴尔的摩港综合沉积物质量评估的一部分，McGee等人（1999年
(
41
)
)用
羽毛乳杆菌
在两栖动物的存活率和选定的沉积物相关污染物的浓度之间检测到负相关关系，而在实验室暴露中的存活率与现场密度之间存在非常强的正相关关系
羽毛乳杆菌
在测试地点。10天和28天的现场验证研究
羽毛乳杆菌
麦基和费舍尔的测试（1999年
(
42
)
)在巴尔的摩港，也表明急性毒性、沉积物相关污染物和
就地
底栖生物群落。在这项研究中，慢性28天试验对沉积物污染的敏感性低于急性10天试验；然而，本次评估中使用的喂养方式与中目前建议的喂养方式不同
附件A2
并且可能已经影响了测试结果。修订后的28天试验的现场验证研究
附件A2
尚未进行。
1.12
羽毛细针病毒的慢性沉淀方法:
1.12.1
大多数标准的全沉积物毒性测试都是为了在某些物种中产生致死终点（存活/死亡率），并可能产生亚致死终点（重新埋葬）（美国环境保护局1994a
(
1.
)
，2001年使用
(
2.
)
). 测量亚致死效应的方法尚不可用，也没有常规用于评估海洋或河口沉积物中的沉积物毒性（Scott和Redmond，1989
(
12
)
; 格林和钱德勒，1996年
(
43
)
; Levin等人，1996年
(
44
)
; Ciarelli等人，1998年
(
45
)
; Meador和Rice，2001年
(
46
)
). 大多数受污染沉积物的评估依赖于短期致死性测试（例如，
≤
10天；USEPA-USACE，1991年
(
47
)
; 1998
(
48
)
). 短期致死性测试有助于识别沉积物污染的“热点”，但可能不够敏感，无法评估中度污染地区。然而，利用海底生物的亚致死反应（如对生长和繁殖的影响）进行的沉积物质量评估已被用于成功评估中度污染地区（Ingersoll等人，1998年
(
49
)
; Kemble等人，1994年
(
50
)
; McGee等人，1995年
(
51
)
; 斯科特，1989年
(
52
)
). 28天毒性试验
羽毛细针介
有两个亚致死终点:生长和繁殖。这些亚致死终点有可能表现出化学物质的毒性反应，否则在测试中可能不会引起急性影响或显著死亡。亚致死性对慢性暴露的反应对于污染物影响的群体建模也很有价值。这些数据可用于海底污染物影响的种群水平风险评估。
1.12.2
对
羽毛乳杆菌
在切萨皮克湾，表明其分布与沉积物污染程度呈负相关（Pfitzenmeyer，1975
(
53
)
; Reinharz，1981年
(
54
)
). 对10-
和28天
羽毛乳杆菌
麦基和费舍尔的测试（1999年
(
42
)
)在巴尔的摩港，表明急性毒性、沉积物相关污染物和
就地
底栖生物群落。在这项研究中，慢性28天试验对沉积物污染的敏感性低于急性10天试验，因此沉积物污染物与底栖生物群落健康之间的相关性较差。需要注意的是，本次评估中使用的喂养方式与中目前建议的喂养方式不同
附件A2
并且可能已经影响了测试结果。尚未进行修订后的28天试验的现场验证研究。
1.13
限制-
虽然本标准中包含了一些安全考虑因素，但包含进行沉积物测试所需的所有安全要求超出了本标准的范围。
1.14
本标准安排如下:
部分
参考文件
2.
术语
3.
标准摘要
4.
意义和用途
5.
干扰
6.
试剂和材料
7.
危害
8.
设施、设备和用品
9
样品采集、储存、操作和表征
10
质量保证和质量控制
11
试验生物的收集、培养和维护
12
计算
13
汇报
14
精度和偏差
15
关键词
16
附件
A1.用两栖类动物进行10天沉积物存活试验的程序
Ampelisca abdita、Eohaustorius河口鱼、Leptocheirus plumulousus，
或
阿氏Rhepoxynius abronius阿氏Rheoxynius
附件A1
A2.执行程序
一种羽毛细针介
28-d用于测量沉积物亚致死效应的沉积物-
相关污染物。
附件A2
工具书类
1.15
本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全和健康实践，并确定监管限制的适用性。
具体危害说明见第节
8.
.
1.16
本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。
====意义和用途======
5.1
概述:
5.1.1
沉积物为许多水生生物提供了栖息地，也是引入地表水中的许多更持久的化学物质的主要储存库。在水生环境中，大多数人为化学物质和废物，包括有毒的有机和无机化学物质，最终都会在沉积物中积累。越来越多的证据表明，美国环保局水质标准（WQC；Stephan等人。
(
66
)
)没有超过，但沉积物中或附近的生物受到不利影响，Chapman，1989
(
67
)
开发WQC是为了保护水柱中的生物，而不是针对保护沉积物中的生物。沉积物中的污染物浓度可能比上覆水中的污染物浓度高几个数量级；
然而，全沉积物浓度与生物利用度之间并没有很强的相关性Burton，1991
(
68
)
化合物在水和沉积物之间的分配或吸附可能取决于许多因素，包括:水溶性、pH、氧化还原、对沉积物有机碳和溶解有机碳的亲和力、沉积物的粒度、沉积物矿物成分（铁、锰和铝的氧化物）以及沉积物中酸挥发性硫化物的数量Di-Toro等人1991
(
69
)
Giesy等人1988
(
70
)
尽管某些化学物质被沉积物高度吸附，但这些化合物仍可能被生物群所利用。沉积物中的化学物质可能对水生生物直接有毒，也可能是食物链中生物累积的化学物质来源。
5.1.2
沉积物测试的目的是确定沉积物中的化学物质是否对底栖生物有害或具有生物累积性。该试验可用于测量沉积物中复杂化学混合物的相互作用毒性效应。此外，沉积物和测试生物之间相互作用的特定途径的知识对于进行测试是不必要的。Kemp等人1988，
(
71
)
沉积物测试可用于:
(1)
确定毒性作用与生物利用度之间的关系，
(2)
研究化学物质之间的相互作用，
(3)
比较不同生物体的敏感性，
(4)
确定污染的空间和时间分布，
(5)
评估疏浚物的危害，
(6)
作为产品许可或安全测试的一部分测量毒性，
(7)
对清理区域进行排名，以及
(8)
评估补救措施或管理实践的有效性。
5.1.3
已经开发了多种方法来评估沉积物中化学物质的毒性，这些方法包括片脚类、侏儒类、多毛类、寡毛类、蜉蝣类或枝角类（试验方法
第1706页
指导
1525欧元
指导
1850欧元
;
附件A1
,
附件A2
; 乌塞帕，2000年
(
72
)
，美国环保局1994b，
(
73
)
，加拿大环境部1997a，
(
74
)
，加拿大环境部1997b，
(
75
)
). 在这些方法中提出了几个终点，以测量沉积物中污染物的潜在影响，包括生存、生长、行为或繁殖；然而，受试生物在10天暴露中的存活率是最常报道的终点。这些短期暴露只能测量对生存的影响，可以用来确定沉积物中的高污染水平，但可能无法确定沉积物中中等污染水平（美国环境保护局，美国环境保护署，2000年
(
72
)
; Sibley等人1996年，
(
76
)
; Sibley等人197a，
(
77
)
; Sibley等人197b，
(
78
)
; Benoit等人1997年，
(
79
)
; Ingersoll等人1998年，
(
80
)
). 沉积物测试中的亚致死量终点也可能被证明是对海底群落对现场污染物反应的更好估计，Kembel等人，1994
(
81
)
。没有足够的信息来确定是否使用
羽毛细针介
(
附件A2
)比用这种或其他物种进行的10天毒性试验更敏感。
5.1.3.1
进行短期或长期毒性试验的决定取决于评估的目标。在某些情况下，通过测量10个亚致死终点可以获得足够的信息-
日间测试。在其他情况下，在进行长期测试之前，可以使用10天的测试来筛选样本的毒性。虽然需要进行长期测试来确定对繁殖的直接影响，但这些毒性测试中的生长测量可以作为与沉积物相关的污染物对繁殖影响的间接估计(
附件A1
).
5.1.3.2
使用亚致死终点评估污染物风险并不是沉积物毒性测试独有的。许多监管计划要求在决策过程中使用亚致死终点（Pittinger和Adams，1997，
(
82
)
)包括:
(1)
水质标准（和国家标准）；
(2)
国家污染物排放消除系统（NPDES）污水监测（包括化学品-
毒性试验中的特定限值和亚致死终点）；
(3)
《联邦杀虫剂、灭鼠剂和杀菌剂法》（FIFRA）和《有毒物质控制法》（TSCA，分级评估包括鱼类和水生无脊椎动物的几个亚致死终点）；
(4)
超级基金（综合环境应对、赔偿和责任法；CERCLA）；
(5)
经济合作与发展组织（经合组织，鱼类和无脊椎动物的亚致死毒性试验）；
(6)
欧洲经济共同体（欧共体，鱼类和无脊椎动物的亚致死毒性试验）；和
(7)
巴黎委员会（行为终点）。
5.1.4
对掺入不同浓度化学品的沉积物进行毒性测试的结果可用于确定化学品和生物反应之间的因果关系。
将试验材料以不同浓度掺入沉积物的毒性试验结果可按LC50（半数致死浓度）、EC50（半数效应浓度）、IC50（抑制浓度）或NOEC（无观测效应浓度）或LOEC（最低观测效应浓度。然而，掺入的沉积物可能不能代表与现场沉积物相关的化学物质。混合时间Stemmer等人1990b，
(
83
)
，老化（Landrum等人1989，
(
84
)
，Word等人1987，
(
85
)
，Landrum等人，1992年，
(
86
)
)，并且材料的化学形式会影响测试生物在加标沉积物测试中的反应。
5.1.5
评估沉积物中化学物质的效应浓度需要了解控制其生物利用度的因素。
以每质量沉积物干重化学物质的质量为单位的类似浓度的化学物质在不同的沉积物中通常表现出一定范围的毒性Di-Toro等人1990，
(
87
)
Di-Toro等人1991，
(
69
)
沉积物中化学物质的效应浓度与间隙水浓度相关，间隙水中的效应浓度通常与仅暴露于水中的效应浓度相似。沉积物中非离子有机化合物的生物利用度通常与有机碳浓度呈负相关。无论暴露途径如何，这些效应浓度与间质水浓度的相关性表明，间质水中的预测或测量浓度可用于量化对生物体的暴露浓度。
因此，关于沉积物固相和液相之间化学物质分配的信息有助于确定效应浓度Di-Toro等人，1991，
(
69
)
.
5.1.6
现场调查可以设计为对沉积物污染的分布进行定性调查，也可以对现场之间的污染进行定量统计比较。
5.1.7
沉积物毒性调查通常是对生物、化学、地质和水文数据进行更全面分析的一部分。如果同时采集子样本进行沉积物测试、化学分析和底栖生物群落结构，则可以提高统计相关性，降低采样成本。
5.1.8
表2
列出了美国环境保护局为评估沉积物质量而考虑的几种方法，1992年，
(
88
)
这些方法包括:
(1)
平衡分配，
(2)
组织残留物，
(3)
间质水毒性，
(4)
全沉积物毒性和沉积物加标试验，
(5)
底栖生物群落结构，
(6)
影响范围（例如，影响范围中位数，ERM），以及
(7)
沉积物质量三元组（见美国环境保护局，1989a、1990a、1990p和1992b(
89
,
90
,
91
,
92
以及Wenning和Ingersoll（2002年
(
93
)
)对这些方法的批评）。中列出的泥沙评估方法
表2
可以分类为数值（例如，平衡划分）、描述性（例如，全沉积物毒性试验）或数值和描述性方法的组合（例如，ERM，美国环保局，1992c，
(
94
)
.可以使用数值方法推导化学-
特定沉积物质量指南（SQG）。不能单独使用描述性方法，如对现场收集的沉积物进行毒性测试，来开发单个化学品的数值SQG。尽管每种方法都可以用于做出特定地点的决策，但没有一种方法能够充分解决沉积物质量问题。总的来说，使用证据的权重综合几种方法是评估与沉积物相关的污染物影响的最理想方法（Long等人，1991
(
95
)
麦克唐纳等人，1996年
(
96
)
Ingersoll等人1996
(
97
)
Ingersoll等人1997
(
98
)
，温宁和英格索尔2002
(
93
)
). 综合了实验室暴露、化学分析和底栖生物群落评估（沉积物质量三元组）数据的危害评估为污染程度提供了有力的补充证据-
水生生物群落的诱导退化（伯顿，1991年
(
68
)
，查普曼19921997
(
99
,
100
)
.)
5.2
监管应用程序-
试验方法
第1706页
提供了沉积物毒性试验的监管应用信息。
5.3
基于性能的标准:
5.3.1
美国环保局环境监测管理委员会（EMMC）建议在制定标准时使用基于绩效的方法（Williams，1993
(
101
)
EMMC将基于性能的方法定义为一种监控方法，允许使用符合预先制定的已证明性能标准的适当方法(
11.2
).
5.3.2
美国环保局水资源办公室、科学技术办公室和研发办公室举办了一次研讨会，为沉积物毒理学领域的专家以及美国环保局地区和总部项目办公室的工作人员提供了一个机会，讨论标准淡水、河口和海洋沉积物测试程序的制定（美国环保局，1992a，1994a
(
88
,
102
)
). 工作组参与者就几种培养和测试方法达成了共识。在制定将被纳入美国环保局沉积物测试方法手册的测试生物培养指南时，一致认为不需要一种方法来培养生物。然而，研讨会上的共识是，测试的成功取决于文化的健康。因此，拥有已知质量和年龄的健康测试生物体进行测试被确定为与培养方法相关的关键考虑因素。美国环保局于2000年选择了一种基于绩效的标准方法
(
72
)
作为优选的方法，通过该方法单个实验室可以使用独特的培养方法，而不需要使用一种培养方法。
5.3.3
本标准建议使用基于绩效的标准，以使每个实验室能够优化培养方法，并最大限度地减少测试生物健康对测试结果可靠性和可比性的影响。看见
附件A1
和
附件A2
用于列出用于培养或测试的性能标准。

1.1
This test method covers procedures for testing estuarine or marine organisms in the laboratory to evaluate the toxicity of contaminants associated with whole sediments. Sediments may be collected from the field or spiked with compounds in the laboratory. General guidance is presented in Sections
1 –
15
for conducting sediment toxicity tests with estuarine or marine amphipods. Specific guidance for conducting 10-d sediment toxicity tests with estuarine or marine amphipods is outlined in
Annex A1
and specific guidance for conducting 28-d sediment toxicity tests with
Leptocheirus plumulosus
is outlined in
Annex A2
.
1.2
Procedures are described for testing estuarine or marine amphipod crustaceans in 10-d laboratory exposures to evaluate the toxicity of contaminants associated with whole sediments (
Annex A1
; USEPA 1994a
(
1
)
). Sediments may be collected from the field or spiked with compounds in the laboratory. A toxicity method is outlined for four species of estuarine or marine sediment-burrowing amphipods found within United States coastal waters. The species are
Ampelisca abdita
, a marine species that inhabits marine and mesohaline portions of the Atlantic coast, the Gulf of Mexico, and San Francisco Bay;
Eohaustorius estuarius
, a Pacific coast estuarine species;
Leptocheirus plumulosus
, an Atlantic coast estuarine species; and
Rhepoxynius abronius
, a Pacific coast marine species. Generally, the method described may be applied to all four species, although acclimation procedures and some test conditions (that is, temperature and salinity) will be species-specific (Sections
12
and
Annex A1
). The toxicity test is conducted in 1-L glass chambers containing 175 mL of sediment and 775 mL of overlying seawater. Exposure is static (that is, water is not renewed), and the animals are not fed over the 10-d exposure period. The endpoint in the toxicity test is survival with reburial of surviving amphipods as an additional measurement that can be used as an endpoint for some of the test species (for
R. abronius
and
E. estuarius
). Performance criteria established for this test include the average survival of amphipods in negative control treatment must be greater than or equal to 90 %. Procedures are described for use with sediments with pore-water salinity ranging from >0
o
/
oo
to fully marine.
1.3
A procedure is also described for determining the chronic toxicity of contaminants associated with whole sediments with the amphipod
Leptocheirus plumulosus
in laboratory exposures (
Annex A2
; USEPA-USACE 2001
(
2
)
). The toxicity test is conducted for 28 d in 1-L glass chambers containing 175 mL of sediment and about 775 mL of overlying water. Test temperature is 25° ± 2 °C, and the recommended overlying water salinity is 5
o
/
oo
± 2
o
/
oo
(for test sediment with pore water at 1
o
/
oo
to 10
o
/
oo
) or 20
o
/
oo
± 2
o
/
oo
(for test sediment with pore water >10
o
/
oo
). Four hundred millilitres of overlying water is renewed three times per week, at which times test organisms are fed. The endpoints in the toxicity test are survival, growth, and reproduction of amphipods. Performance criteria established for this test include the average survival of amphipods in negative control treatment must be greater than or equal to 80 % and there must be measurable growth and reproduction in all replicates of the negative control treatment. This test is applicable for use with sediments from oligohaline to fully marine environments, with a silt content greater than 5 % and a clay content less than 85 %.
1.4
A salinity of 5 or 20
o
/
oo
is recommended for routine application of 28-d test with
L. plumulosus
(
Annex A2
; USEPA-USACE 2001
(
2
)
) and a salinity of 20
o
/
oo
is recommended for routine application of the 10-d test with
E. estuarius
or
L. plumulosus
(
Annex A1
). However, the salinity of the overlying water for tests with these two species can be adjusted to a specific salinity of interest (for example, salinity representative of site of interest or the objective of the study may be to evaluate the influence of salinity on the bioavailability of chemicals in sediment). More importantly, the salinity tested must be within the tolerance range of the test organisms (as outlined in
Annex A1
and
Annex A2
). If tests are conducted with procedures different from those described in
1.3
or in
Table A1.1
(for example, different salinity, lighting, temperature, feeding conditions), additional tests are required to determine comparability of results (
1.10
). If there is not a need to make comparisons among studies, then the test could be conducted just at a selected salinity for the sediment of interest.
1.5
Future revisions of this standard may include additional annexes describing whole-sediment toxicity tests with other groups of estuarine or marine invertebrates (for example, information presented in Guide
E1611
on sediment testing with polychaetes could be added as an annex to future revisions to this standard). Future editions to this standard may also include methods for conducting the toxicity tests in smaller chambers with less sediment (Ho et al. 2000
(
3
)
, Ferretti et al. 2002
(
4
)
).
1.6
Procedures outlined in this standard are based primarily on procedures described in the USEPA (1994a
(
1
)
), USEPA-USACE (2001
(
2
)
), Test Method
E1706
, and Guides
E1391
,
E1525
,
E1688
, Environment Canada (1992
(
5
)
), DeWitt et al. (1992a
(
6
)
; 1997a
(
7
)
), Emery et al. (1997
(
8
)
), and Emery and Moore (1996
(
9
)
), Swartz et al. (1985
(
10
)
), DeWitt et al. (1989
(
11
)
), Scott and Redmond (1989
(
12
)
), and Schlekat et al. (1992
(
13
)
).
1.7
Additional sediment toxicity research and methods development are now in progress to
(1)
refine sediment spiking procedures,
(2)
refine sediment dilution procedures,
(3)
refine sediment Toxicity Identification Evaluation (TIE) procedures,
(4)
produce additional data on confirmation of responses in laboratory tests with natural populations of benthic organisms (that is, field validation studies), and
(5)
evaluate relative sensitivity of endpoints measured in 10- and 28-d toxicity tests using estuarine or marine amphipods. This information will be described in future editions of this standard.
1.8
Although standard procedures are described in
Annex A2
of this standard for conducting chronic sediment tests with
L. plumulosus
, further investigation of certain issues could aid in the interpretation of test results. Some of these issues include further investigation to evaluate the relative toxicological sensitivity of the lethal and sublethal endpoints to a wide variety of chemicals spiked in sediment and to mixtures of chemicals in sediments from contamination gradients in the field (USEPA-USACE 2001
(
2
)
). Additional research is needed to evaluate the ability of the lethal and sublethal endpoints to estimate the responses of populations and communities of benthic invertebrates to contaminated sediments. Research is also needed to link the toxicity test endpoints to a field-validated population model of
L. plumulosus
that would then generate estimates of population-level responses of the amphipod to test sediments and thereby provide additional ecologically relevant interpretive guidance for the laboratory toxicity test.
1.9
This standard outlines specific test methods for evaluating the toxicity of sediments with
A. abdita
,
E. estuarius
,
L. plumulosus
, and
R. abronius
. While standard procedures are described in this standard, further investigation of certain issues could aid in the interpretation of test results. Some of these issues include the effect of shipping on organism sensitivity, additional performance criteria for organism health, sensitivity of various populations of the same test species, and confirmation of responses in laboratory tests with natural benthos populations.
1.10
General procedures described in this standard might be useful for conducting tests with other estuarine or marine organisms (for example,
Corophium spp.
,
Grandidierella japonica
,
Lepidactylus dytiscus
,
Streblospio benedicti
), although modifications may be necessary. Results of tests, even those with the same species, using procedures different from those described in the test method may not be comparable and using these different procedures may alter bioavailability. Comparison of results obtained using modified versions of these procedures might provide useful information concerning new concepts and procedures for conducting sediment tests with aquatic organisms. If tests are conducted with procedures different from those described in this test method, additional tests are required to determine comparability of results. General procedures described in this test method might be useful for conducting tests with other aquatic organisms; however, modifications may be necessary.
1.11
Selection of Toxicity Testing Organisms:
1.11.1
The choice of a test organism has a major influence on the relevance, success, and interpretation of a test. Furthermore, no one organism is best suited for all sediments. The following criteria were considered when selecting test organisms to be described in this standard (
Table 1
and Guide
E1525
). Ideally, a test organism should:
(1)
have a toxicological database demonstrating relative sensitivity to a range of contaminants of interest in sediment,
(2)
have a database for interlaboratory comparisons of procedures (for example, round-robin studies),
(3)
be in direct contact with sediment,
(4)
be readily available from culture or through field collection,
(5)
be easily maintained in the laboratory,
(6)
be easily identified,
(7)
be ecologically or economically important,
(8)
have a broad geographical distribution, be indigenous (either present or historical) to the site being evaluated, or have a niche similar to organisms of concern (for example, similar feeding guild or behavior to the indigenous organisms),
(9)
be tolerant of a broad range of sediment physico-chemical characteristics (for example, grain size), and
(10)
be compatible with selected exposure methods and endpoints (Guide
E1525
). Methods utilizing selected organisms should also be
(11)
peer reviewed (for example, journal articles) and
(12)
confirmed with responses with natural populations of benthic organisms.
ATL = Atlantic Coast, PAC = Pacific Coast, GOM= Gulf of Mexico
1.11.2
Of these criteria (
Table 1
), a database demonstrating relative sensitivity to contaminants, contact with sediment, ease of culture in the laboratory or availability for field-collection, ease of handling in the laboratory, tolerance to varying sediment physico-chemical characteristics, and confirmation with responses with natural benthic populations were the primary criteria used for selecting
A. abdita
,
E. estuarius
,
L. plumulosus
, and
R. abronius
for the current edition of this standard for 10-d sediment tests (
Annex A1
). The species chosen for this method are intimately associated with sediment, due to their tube- dwelling or free-burrowing, and sediment ingesting nature. Amphipods have been used extensively to test the toxicity of marine, estuarine, and freshwater sediments (Swartz et al., 1985
(
10
)
; DeWitt et al., 1989
(
11
)
; Scott and Redmond, 1989
(
12
)
; DeWitt et al., 1992a
(
6
)
; Schlekat et al., 1992
(
13
)
). The selection of test species for this standard followed the consensus of experts in the field of sediment toxicology who participated in a workshop entitled “Testing Issues for Freshwater and Marine Sediments”. The workshop was sponsored by USEPA Office of Water, Office of Science and Technology, and Office of Research and Development, and was held in Washington, D.C. from 16-18 September 1992 (USEPA, 1992
(
15
)
). Of the candidate species discussed at the workshop,
A. abdita
,
E. estuarius
,
L. plumulosus
, and
R. abronius
best fulfilled the selection criteria, and presented the availability of a combination of one estuarine and one marine species each for both the Atlantic (the estuarine
L. plumulosus
and the marine
A. abdita
) and Pacific (the estuarine
E. estuarius
and the marine
R. abronius
) coasts.
Ampelisca abdita
is also native to portions of the Gulf of Mexico and San Francisco Bay. Many other organisms that might be appropriate for sediment testing do not now meet these selection criteria because little emphasis has been placed on developing standardized testing procedures for benthic organisms. For example, a fifth species,
Grandidierella japonica
was not selected because workshop participants felt that the use of this species was not sufficiently broad to warrant standardization of the method. Environment Canada (1992
(
5
)
) has recommended the use of the following amphipod species for sediment toxicity testing:
Amphiporeia virginiana
,
Corophium volutator
,
Eohaustorius washingtonianus
,
Foxiphalus xiximeus
, and
Leptocheirus pinguis
. A database similar to those available for
A. abdita
,
E. estuarius
,
L. plumulosus
, and
R. abronius
must be developed in order for these and other organisms to be included in future editions of this standard.
1.11.3
The primary criterion used for selecting
L. plumulosus
for chronic testing of sediments was that this species is found in both oligohaline and mesohaline regions of estuaries on the East Coast of the United States and is tolerant to a wide range of sediment grain size distribution (USEPA-USACE 2001
(
2
)
, Annex
Annex A2
). This species is easily cultured in the laboratory and has a relatively short generation time (that is, about 24 d at 23 °C, DeWitt et al. 1992a
(
6
)
) that makes this species adaptable to chronic testing (Section
12
).
1.11.4
An important consideration in the selection of specific species for test method development is the existence of information concerning relative sensitivity of the organisms both to single chemicals and complex mixtures. Several studies have evaluated the sensitivities of
A. abdita
,
E. estuarius
,
L. plumulosus
, or
R. abronius
, either relative to one another, or to other commonly tested estuarine or marine species. For example, the sensitivity of marine amphipods was compared to other species that were used in generating saltwater Water Quality Criteria. Seven amphipod genera, including
Ampelisca abdita
and
Rhepoxynius abronius
, were among the test species used to generate saltwater Water Quality Criteria for 12 chemicals. Acute amphipod toxicity data from 4-d water-only tests for each of the 12 chemicals was compared to data for
(1)
all other species,
(2)
other benthic species, and
(3)
other infaunal species. Amphipods were generally of median sensitivity for each comparison. The average percentile rank of amphipods among all species tested was 57 %; among all benthic species, 56 %; and, among all infaunal species, 54 %. Thus, amphipods are not uniquely sensitive relative to all species, benthic species, or even infaunal species (USEPA 1994a
(
1
)
). Additional research may be warranted to develop tests using species that are consistently more sensitive than amphipods, thereby offering protection to less sensitive groups.
1.11.5
Williams et al. (1986
(
16
)
) compared the sensitivity of the
R. abronius
10-d whole sediment test, the oyster embryo (
Crassostrea gigas
) 48-h abnormality test, and the bacterium (
Vibrio fisheri
) 1-h luminescence inhibition test (that is, the Microtox
2
test) to sediments collected from 46 contaminated sites in Commencement Bay, WA.
Rhepoxynius abronius
were exposed to whole sediment, while the oyster and bacterium tests were conducted with sediment elutriates and extracts, respectfully. Microtox
2
was the most sensitive test, with 63 % of the sites eliciting significant inhibition of luminescence. Significant mortality of
R. abronius
was observed in 40 % of test sediments, and oyster abnormality occurred in 35 % of sediment elutriates. Complete concordance (that is, sediments that were either toxic or not-toxic in all three tests) was observed in 41 % of the sediments. Possible sources for the lack of concordance at other sites include interspecific differences in sensitivity among test organisms, heterogeneity in contaminant types associated with test sediments, and differences in routes of exposure inherent in each toxicity test. These results highlight the importance of using multiple assays when performing sediment assessments.
1.11.6
Several studies have compared the sensitivity of combinations of the four amphipods to sediment contaminants. For example, there are several comparisons between
A. abdita
and
R. abronius
, between
E. estuarius
and
R. abronius
, and between
A. abdita
and
L. plumulosus
. There are fewer examples of direct comparisons between
E. estuarius
and
L. plumulosus
, and no examples comparing
L. plumulosus
and
R. abronius
. There is some overlap in relative sensitivity from comparison to comparison within each species combination, which appears to indicate that all four species are within the same range of relative sensitivity to contaminated sediments.
1.11.6.1
Word et al. (1989
(
17
)
) compared the sensitivity of
A. abdita
and
R. abronius
to contaminated sediments in a series of experiments. Both species were tested at 15 °C. Experiments were designed to compare the response of the organism rather than to provide a comparison of the sensitivity of the methods (that is,
Ampelisca abdita
would normally be tested at 20 °C). Sediments collected from Oakland Harbor, CA, were used for the comparisons. Twenty-six sediments were tested in one comparison, while 5 were tested in the other. Analysis of results using Kruskal Wallace rank sum test for both experiments demonstrated that
R. abronius
exhibited greater sensitivity to the sediments than
A. abdita
at 15 °C. Long and Buchman (1989
(
18
)
) also compared the sensitivity of
A. abdita
and
R. abronius
to sediments from Oakland Harbor, CA. They also determined that
A. abdita
showed less sensitivity than
R. abronius
, but they also showed that
A. abdita
was less sensitive to sediment grain size factors than
R. abronius
.
1.11.6.2
DeWitt et al. (1989
(
11
)
) compared the sensitivity of
E. estuarius
and
R. abronius
to sediment spiked with fluoranthene and field-collected sediment from industrial waterways in Puget Sound, WA, in 10-d tests, and to aqueous cadmium (CdCl
2
) in a 4-d water-only test. The sensitivity of
E. estuarius
was from two (to spiked-spiked sediment) to seven (to one Puget Sound, WA, sediment) times less sensitive than
R. abronius
in sediment tests, and ten times less sensitive to CdCl
2
in the water-only test. These results are supported by the findings of Pastorok and Becker (1990
(
19
)
) who found the acute sensitivity of
E. estuarius
and
R. abronius
to be generally comparable to each other, and both were more sensitive than
Neanthes arenaceodentata
(survival and biomass endpoints),
Panope generosa
(survival), and
Dendraster excentricus
(survival).
1.11.6.3
Leptocheirus plumulosus
was as sensitive as the freshwater amphipod
Hyalella azteca
to an artificially created gradient of sediment contamination when the latter was acclimated to oligohaline salinity (that is, 6
o
/
oo
; McGee et al., 1993
(
20
)
). DeWitt et al. (1992b
(
21
)
) compared the sensitivity of
L. plumulosus
with three other amphipod species, two mollusks, and one polychaete to highly contaminated sediment collected from Baltimore Harbor, MD, that was serially diluted with clean sediment.
Leptocheirus plumulosus
was more sensitive than the amphipods
Hyalella azteca
and
Lepidactylus dytiscus
and exhibited equal sensitivity with
E. estuarius
. Schlekat et al. (1995
(
22
)
) describe the results of an interlaboratory comparison of 10-d tests with
A. abdita
,
L. plumulosus
and
E. estuarius
using dilutions of sediments collected from Black Rock Harbor, CT. There was strong agreement among species and laboratories in the ranking of sediment toxicity and the ability to discriminate between toxic and non-toxic sediments.
1.11.6.4
Hartwell et al. (2000
(
23
)
) evaluated the response of
Leptocheirus plumulosus
(10-d survival or growth) to the response of the amphipod
Lepidactylus dytiscus
(10-d survival or growth), the polychaete
Streblospio benedicti
(10-d survival or growth), and lettuce germination (Lactuca sativa in 3-d exposure) and observed that
L. plumulosus
was relatively insensitive compared to the response of either L. dytiscus or S. benedicti in exposures to 4 sediments with elevated metal concentrations.
1.11.6.5
Ammonia is a naturally occurring compound in marine sediment that results from the degradation of organic debris. Interstitial ammonia concentrations in test sediment can range from <1 mg/L to in excess of 400 mg/L (Word et al., 1997
(
24
)
). Some benthic infauna show toxicity to ammonia at concentrations of about 20 mg/L (Kohn et al., 1994
(
25
)
). Based on water-only and spiked-sediment experiments with ammonia, threshold limits for test initiation and termination have been established for the
L. plumulosus
chronic test. Smaller (younger) individuals are more sensitive to ammonia than larger (older) individuals (DeWitt et al., 1997a
(
7
)
, b
(
26
). Results of a 28-d test indicated that neonates can tolerate very high levels of pore-water ammonia (>300 mg/L total ammonia) for short periods of time with no apparent long-term effects (Moore et al., 1997
(
27
)
). It is not surprising
L. plumulosus
has a high tolerance for ammonia given that these amphipods are often found in organic rich sediments in which diagenesis can result in elevated pore-water ammonia concentrations. Insensitivity to ammonia by
L. plumulosus
should not be construed as an indicator of the sensitivity of the
L. plumulosus
sediment toxicity test to other chemicals of concern.
1.11.7
Limited comparative data is available for concurrent water-only exposures of all four species in single-chemical tests. Studies that do exist generally show that no one species is consistently the most sensitive.
1.11.7.1
The relative sensitivity of the four amphipod species to ammonia was determined in ten-d water only toxicity tests in order to aid interpretation of results of tests on sediments where this toxicant is present (USEPA 1994a
(
1
)
). These tests were static exposures that were generally conducted under conditions (for example, salinity, photoperiod) similar to those used for standard 10-d sediment tests. Departures from standard conditions included the absence of sediment and a test temperature of 20 °C for
L. plumulosus
, rather than 25 °C as dictated in this standard. Sensitivity to total ammonia increased with increasing pH for all four species. The rank sensitivity was
R. abronius
=
A. abdita
>
E. estuarius
>
L. plumulosus
. A similar study by Kohn et al. (1994
(
25
)
) showed a similar but slightly different relative sensitivity to ammonia with
A. abdita
>
R. abronius
=
L. plumulosus
>
E. estuarius
.
1.11.7.2
Cadmium chloride has been a common reference toxicant for all four species in 4-d exposures. DeWitt et al. (1992a
(
6
)
) reports the rank sensitivity as
R. abronius
>
A. abdita
>
L. plumulosus
>
E. estuarius
at a common temperature and salinity of 15 °C and 28
o
/
oo
. A series of 4-d exposures to cadmium that were conducted at species-specific temperatures and salinities showed the following rank sensitivity:
A. abdita
=
L. plumulosus
=
R. abronius
>
E. estuarius
(USEPA 1994a
(
1
)
).
1.11.7.3
Relative species sensitivity frequently varies among contaminants; consequently, a battery of tests including organisms representing different trophic levels may be needed to assess sediment quality (Craig, 1984
(
28
)
; Williams et al. 1986
(
16
)
; Long et al., 1990
(
29
)
; Ingersoll et al., 1990
(
30
)
; Burton and Ingersoll, 1994
(
31
)
). For example, Reish (1988
(
32
)
) reported the relative toxicity of six metals (arsenic, cadmium, chromium, copper, mercury, and zinc) to crustaceans, polychaetes, pelecypods, and fishes and concluded that no one species or group of test organisms was the most sensitive to all of the metals.
1.11.8
The sensitivity of an organism is related to route of exposure and biochemical response to contaminants. Sediment-dwelling organisms can receive exposure from three primary sources: interstitial water, sediment particles, and overlying water. Food type, feeding rate, assimilation efficiency, and clearance rate will control the dose of contaminants from sediment. Benthic invertebrates often selectively consume different particle sizes (Harkey et al. 1994
(
33
)
) or particles with higher organic carbon concentrations which may have higher contaminant concentrations. Grazers and other collector-gatherers that feed on aufwuchs and detritus may receive most of their body burden directly from materials attached to sediment or from actual sediment ingestion. In some amphipods (Landrum, 1989
(
34
)
) and clams (Boese et al., 1990
(
35
)
) uptake through the gut can exceed uptake across the gills for certain hydrophobic compounds. Organisms in direct contact with sediment may also accumulate contaminants by direct adsorption to the body wall or by absorption through the integument (Knezovich et al. 1987
(
36
)
).
1.11.9
Despite the potential complexities in estimating the dose that an animal receives from sediment, the toxicity and bioaccumulation of many contaminants in sediment such as Kepone®, fluoranthene, organochlorines, and metals have been correlated with either the concentration of these chemicals in interstitial water or in the case of non-ionic organic chemicals, concentrations in sediment on an organic carbon normalized basis (Di Toro et al. 1990
(
37
)
; Di Toro et al. 1991
(
38
)
). The relative importance of whole sediment and interstitial water routes of exposure depends on the test organism and the specific contaminant (Knezovich et al. 1987
(
36
)
). Because benthic communities contain a diversity of organisms, many combinations of exposure routes may be important. Therefore, behavior and feeding habits of a test organism can influence its ability to accumulate contaminants from sediment and should be considered when selecting test organisms for sediment testing.
1.11.10
The use of
A. abdita
,
E. estuarius
,
R. abronius
, and
L. plumulosus
in laboratory toxicity studies has been field validated with natural populations of benthic organisms (Swartz et al. 1994
(
39
)
and Anderson et al. 2001
(
14
)
for
E. estuarius
, Swartz et al. 1982
(
40
)
and Anderson et al. 2001
(
14
)
for
R. abronius
, McGee et al. 1999
(
41
)
and McGee and Fisher 1999
(
42
)
for
L. plumulosus
).
1.11.10.1
Data from USEPA Office of Research and Development's Environmental Monitoring and Assessment program were examined to evaluate the relationship between survival of
Ampelisca abdita
in sediment toxicity tests and the presence of amphipods, particularly ampeliscids, in field samples. Over 200 sediment samples from two years of sampling in the Virginian Province (Cape Cod, MA, to Cape Henry, VA) were available for comparing synchronous measurements of
A. abdita
survival in toxicity tests to benthic community enumeration. Although species of this genus were among the more frequently occurring taxa in these samples, ampeliscids were totally absent from stations that exhibited
A. abdita
test survival <60 % of that in control samples. Additionally, ampeliscids were found in very low densities at stations with amphipod test survival between 60 and 80 % (USEPA 1994a
(
1
)
). These data indicate that tests with this species are predictive of contaminant effects on sensitive species under natural conditions.
1.11.10.2
Swartz et al. (1982
(
40
)
) compared sensitivity of
R. abronius
to sediment collected from sites in Commencement Bay, WA, to benthic community structure at each site. Mortality of
R. abronius
was negatively correlated with amphipod density, and phoxocephalid amphipods were ubiquitously absent from the most contaminated areas.
1.11.10.3
Sediment toxicity to amphipods in 10-d toxicity tests, field contamination, and field abundance of benthic amphipods were examined along a sediment contamination gradient of DDT (Swartz et al. 1994
(
39
)
). Survival of
E. estuarius
and
R. abronius
in laboratory toxicity tests was positively correlated to abundance of amphipods in the field and along with the survival of
H. azteca
, was negatively correlated to DDT concentrations. The threshold for 10-d sediment toxicity in laboratory studies was about 300 ug DDT (+metabolites)/g organic carbon. The threshold for abundance of amphipods in the field was about 100 ug DDT (+metabolites)/g organic carbon. Therefore, correlations between toxicity, contamination, and biology indicate that acute 10-d sediment toxicity tests can provide reliable evidence of biologically adverse sediment contamination in the field.
1.11.10.4
As part of a comprehensive sediment quality assessment in Baltimore Harbor, MD, McGee et al. (1999
(
41
)
) conducted 10-d toxicity tests with
L. plumulosus
. Negative relationships were detected between amphipod survival and concentrations of select sediment-associated contaminants, whereas a very strong positive association existed between survival in laboratory exposures and field density of
L. plumulosus
at test sites. A field validation study of the 10- and 28-d
L. plumulosus
tests by McGee and Fisher (1999
(
42
)
) in Baltimore Harbor, also indicated good agreement between acute toxicity, sediment associated contaminants and responses of the
in situ
benthic community. In this study, the chronic 28-d test was less sensitive to sediment contamination than the acute 10-d test; however, the feeding regime used in this evaluation is different than the one currently recommended in
Annex A2
and may have influenced the test results. Field validation studies with the revised 28-d test outlined in
Annex A2
have not been conducted.
1.12
Chronic Sediment Methods with Leptocheirus plumulosus:
1.12.1
Most standard whole sediment toxicity tests have been developed to produce a lethality endpoint (survival/mortality) with potential for a sublethal endpoint (reburial) in some species (USEPA 1994a
(
1
)
, USEPA-USACE 2001
(
2
)
). Methods that measure sublethal effects have not been available or have not been routinely used to evaluate sediment toxicity in marine or estuarine sediments (Scott and Redmond, 1989
(
12
)
; Green and Chandler, 1996
(
43
)
; Levin et al., 1996
(
44
)
; Ciarelli et al., 1998
(
45
)
; Meador and Rice, 2001
(
46
)
). Most assessments of contaminated sediment rely on short-term lethality tests (for example,
≤
10 d; USEPA-USACE, 1991
(
47
)
; 1998
(
48
)
). Short-term lethality tests are useful in identifying “hot spots” of sediment contamination, but might not be sensitive enough to evaluate moderately contaminated areas. However, sediment quality assessments using sublethal responses of benthic organisms, such as effects on growth and reproduction, have been used to successfully evaluate moderately contaminated areas (Ingersoll et al., 1998
(
49
)
; Kemble et al., 1994
(
50
)
; McGee et al., 1995
(
51
)
; Scott, 1989
(
52
)
). The 28-d toxicity test with
Leptocheirus plumulosus
has two sublethal endpoints: growth and reproduction. These sublethal endpoints have potential to exhibit a toxic response from chemicals that otherwise might not cause acute effects or significant mortality in a test. Sublethal response to chronic exposure is also valuable for population modeling of contaminant effects. These data can be used for population-level risk assessments of benthic pollutant effects.
1.12.2
An evaluation of the distribution of
L. plumulosus
in Chesapeake Bay indicates that its distribution is negatively correlated with the degree of sediment contamination (Pfitzenmeyer, 1975
(
53
)
; Reinharz, 1981
(
54
)
). A field validation study of the 10- and 28-d
L. plumulosus
tests by McGee and Fisher (1999
(
42
)
) in Baltimore Harbor, indicated good agreement between acute toxicity, sediment associated contaminants and responses of the
in situ
benthic community. In this study, the chronic 28-d test was less sensitive to sediment contamination than the acute 10-d test and therefore had a poorer association between sediment contaminants and benthic community health. It should be noted that the feeding regime used in this evaluation is different than the one currently recommended in
Annex A2
and may have influenced the test results. Field validation studies with the revised 28-d test have not been conducted.
1.13
Limitations—
While some safety considerations are included in this standard, it is beyond the scope of this standard to encompass all safety requirements necessary to conduct sediment tests.
1.14
This standard is arranged as follows:
Section
Referenced Documents
2
Terminology
3
Summary of Standard
4
Significance and Use
5
Interferences
6
Reagents and Materials
7
Hazards
8
Facilities, Equipment, and Supplies
9
Sample Collection, Storage, Manipulation, and Characterization
10
Quality Assurance and Quality Control
11
Collection, Culturing, and Maintaining Test Organisms
12
Calculation
13
Report
14
Precision and Bias
15
Keywords
16
Annexes
A1. Procedure For Conducting A 10-d Sediment Survival Test With the Amphipods
Ampelisca abdita, Eohaustorius estuarius, Leptocheirus plumulosus,
, or
Rhepoxynius abronius
Annex A1
A2. Procedure For Conducting
A Leptocheirus plumulosus
28-d Sediment For Measuring Sublethal Effects of Sediment-Associated Contaminants.
Annex A2
References
1.15
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Specific hazard statements are given in Section
8
.
1.16
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
 ====== Significance And Use ======
5.1
General:
5.1.1
Sediment provides habitat for many aquatic organisms and is a major repository for many of the more persistent chemicals that are introduced into surface waters. In the aquatic environment, most anthropogenic chemicals and waste materials including toxic organic and inorganic chemicals eventually accumulate in sediment. Mounting evidences exists of environmental degradation in areas where USEPA Water Quality Criteria (WQC; Stephan et al.
(
66
)
) are not exceeded, yet organisms in or near sediments are adversely affected Chapman, 1989
(
67
)
. The WQC were developed to protect organisms in the water column and were not directed toward protecting organisms in sediment. Concentrations of contaminants in sediment may be several orders of magnitude higher than in the overlying water; however, whole sediment concentrations have not been strongly correlated to bioavailability Burton, 1991
(
68
)
. Partitioning or sorption of a compound between water and sediment may depend on many factors including: aqueous solubility, pH, redox, affinity for sediment organic carbon and dissolved organic carbon, grain size of the sediment, sediment mineral constituents (oxides of iron, manganese, and aluminum), and the quantity of acid volatile sulfides in sediment Di Toro et al. 1991
(
69
)
Giesy et al. 1988
(
70
)
. Although certain chemicals are highly sorbed to sediment, these compounds may still be available to the biota. Chemicals in sediments may be directly toxic to aquatic life or can be a source of chemicals for bioaccumulation in the food chain.
5.1.2
The objective of a sediment test is to determine whether chemicals in sediment are harmful to or are bioaccumulated by benthic organisms. The tests can be used to measure interactive toxic effects of complex chemical mixtures in sediment. Furthermore, knowledge of specific pathways of interactions among sediments and test organisms is not necessary to conduct the tests Kemp et al. 1988,
(
71
)
. Sediment tests can be used to:
(1)
determine the relationship between toxic effects and bioavailability,
(2)
investigate interactions among chemicals,
(3)
compare the sensitivities of different organisms,
(4)
determine spatial and temporal distribution of contamination,
(5)
evaluate hazards of dredged material,
(6)
measure toxicity as part of product licensing or safety testing,
(7)
rank areas for clean up, and
(8)
estimate the effectiveness of remediation or management practices.
5.1.3
A variety of methods have been developed for assessing the toxicity of chemicals in sediments using amphipods, midges, polychaetes, oligochaetes, mayflies, or cladocerans (Test Method
E1706
, Guide
E1525
, Guide
E1850
;
Annex A1
,
Annex A2
; USEPA, 2000
(
72
)
, EPA 1994b,
(
73
)
, Environment Canada 1997a,
(
74
)
, Enviroment Canada 1997b,
(
75
)
). Several endpoints are suggested in these methods to measure potential effects of contaminants in sediment including survival, growth, behavior, or reproduction; however, survival of test organisms in 10-day exposures is the endpoint most commonly reported. These short-term exposures that only measure effects on survival can be used to identify high levels of contamination in sediments, but may not be able to identify moderate levels of contamination in sediments (USEPA USEPA, 2000
(
72
)
; Sibley et al.1996,
(
76
)
; Sibley et al.1997a,
(
77
)
; Sibley et al.1997b,
(
78
)
; Benoit et al.1997,
(
79
)
; Ingersoll et al.1998,
(
80
)
). Sublethal endpoints in sediment tests might also prove to be better estimates of responses of benthic communities to contaminants in the field, Kembel et al. 1994
(
81
)
. Insufficient information is available to determine if the long-term test conducted with
Leptocheirus plumulosus
(
Annex A2
) is more sensitive than 10-d toxicity tests conducted with this or other species.
5.1.3.1
The decision to conduct short-term or long-term toxicity tests depends on the goal of the assessment. In some instances, sufficient information may be gained by measuring sublethal endpoints in 10-day tests. In other instances, the 10-day tests could be used to screen samples for toxicity before long-term tests are conducted. While the long-term tests are needed to determine direct effects on reproduction, measurement of growth in these toxicity tests may serve as an indirect estimate of reproductive effects of contaminants associated with sediments (
Annex A1
).
5.1.3.2
Use of sublethal endpoints for assessment of contaminant risk is not unique to toxicity testing with sediments. Numerous regulatory programs require the use of sublethal endpoints in the decision-making process (Pittinger and Adams, 1997,
(
82
)
) including:
(1)
Water Quality Criteria (and State Standards);
(2)
National Pollution Discharge Elimination System (NPDES) effluent monitoring (including chemical-specific limits and sublethal endpoints in toxicity tests);
(3)
Federal Insecticide, Rodenticide and Fungicide Act (FIFRA) and the Toxic Substances Control Act (TSCA, tiered assessment includes several sublethal endpoints with fish and aquatic invertebrates);
(4)
Superfund (Comprehensive Environmental Responses, Compensation and Liability Act; CERCLA);
(5)
Organization of Economic Cooperation and Development (OECD, sublethal toxicity testing with fish and invertebrates);
(6)
European Economic Community (EC, sublethal toxicity testing with fish and invertebrates); and
(7)
the Paris Commission (behavioral endpoints).
5.1.4
Results of toxicity tests on sediments spiked at different concentrations of chemicals can be used to establish cause and effect relationships between chemicals and biological responses. Results of toxicity tests with test materials spiked into sediments at different concentrations may be reported in terms of an LC50 (median lethal concentration), an EC50 (median effect concentration), an IC50 (inhibition concentration), or as a NOEC (no observed effect concentration) or LOEC (lowest observed effect concentration). However, spiked sediment may not be representative of chemicals associated with sediment in the field. Mixing time Stemmer et al. 1990b,
(
83
)
, aging ( Landrum et al. 1989,
(
84
)
, Word et al. 1987,
(
85
)
, Landrum et al., 1992,
(
86
)
), and the chemical form of the material can affect responses of test organisms in spiked sediment tests.
5.1.5
Evaluating effect concentrations for chemicals in sediment requires knowledge of factors controlling their bioavailability. Similar concentrations of a chemical in units of mass of chemical per mass of sediment dry weight often exhibit a range in toxicity in different sediments Di Toro et al. 1990,
(
87
)
Di Toro et al. 1991,
(
69
)
. Effect concentrations of chemicals in sediment have been correlated to interstitial water concentrations, and effect concentrations in interstitial water are often similar to effect concentrations in water-only exposures. The bioavailability of nonionic organic compounds in sediment is often inversely correlated with the organic carbon concentration. Whatever the route of exposure, these correlations of effect concentrations to interstitial water concentrations indicate that predicted or measured concentrations in interstitial water can be used to quantify the exposure concentration to an organism. Therefore, information on partitioning of chemicals between solid and liquid phases of sediment is useful for establishing effect concentrations Di Toro et al. 1991,
(
69
)
.
5.1.6
Field surveys can be designed to provide either a qualitative reconnaissance of the distribution of sediment contamination or a quantitative statistical comparison of contamination among sites.
5.1.7
Surveys of sediment toxicity are usually part of more comprehensive analyses of biological, chemical, geological, and hydrographic data. Statistical correlations may be improved and sampling costs may be reduced if subsamples are taken simultaneously for sediment tests, chemical analyses, and benthic community structure.
5.1.8
Table 2
lists several approaches the USEPA has considered for the assessment of sediment quality USEPA, 1992,
(
88
)
. These approaches include:
(1)
equilibrium partitioning,
(2)
tissue residues,
(3)
interstitial water toxicity,
(4)
whole-sediment toxicity and sediment-spiking tests,
(5)
benthic community structure,
(6)
effect ranges (for example, effect range median, ERM), and
(7)
sediment quality triad (see USEPA, 1989a, 1990a, 1990b and 1992b, (
89
,
90
,
91
,
92
and Wenning and Ingersoll (2002
(
93
)
) for a critique of these methods). The sediment assessment approaches listed in
Table 2
can be classified as numeric (for example, equilibrium partitioning), descriptive (for example, whole-sediment toxicity tests), or a combination of numeric and descriptive approaches (for example, ERM, USEPA, 1992c,
(
94
)
. Numeric methods can be used to derive chemical-specific sediment quality guidelines (SQGs). Descriptive methods such as toxicity tests with field-collected sediment cannot be used alone to develop numerical SQGs for individual chemicals. Although each approach can be used to make site-specific decisions, no one single approach can adequately address sediment quality. Overall, an integration of several methods using the weight of evidence is the most desirable approach for assessing the effects of contaminants associated with sediment, (Long et al. 1991
(
95
)
MacDonald et al. 1996
(
96
)
Ingersoll et al. 1996
(
97
)
Ingersoll et al. 1997
(
98
)
, Wenning and Ingersoll 2002
(
93
)
). Hazard evaluations integrating data from laboratory exposures, chemical analyses, and benthic community assessments (the sediment quality triad) provide strong complementary evidence of the degree of pollution-induced degradation in aquatic communities (Burton, 1991
(
68
)
, Chapman 1992, 1997
(
99
,
100
)
.)
5.2
Regulatory Applications—
Test Method
E1706
provides information on the regulatory applications of sediment toxicity tests.
5.3
Performance-based Criteria:
5.3.1
The USEPA Environmental Monitoring Management Council (EMMC) recommended the use of performance-based methods in developing standards, (Williams, 1993
(
101
)
. Performance-based methods were defined by EMMC as a monitoring approach which permits the use of appropriate methods that meet preestablished demonstrated performance standards (
11.2
).
5.3.2
The USEPA Office of Water, Office of Science and Technology, and Office of Research and Development held a workshop to provide an opportunity for experts in the field of sediment toxicology and staff from the USEPA Regional and Headquarters Program offices to discuss the development of standard freshwater, estuarine, and marine sediment testing procedures (USEPA, 1992a, 1994a
(
88
,
102
)
). Workgroup participants arrived at a consensus on several culturing and testing methods. In developing guidance for culturing test organisms to be included in the USEPA methods manual for sediment tests, it was agreed that no one method should be required to culture organisms. However, the consensus at the workshop was that success of a test depends on the health of the cultures. Therefore, having healthy test organisms of known quality and age for testing was determined to be the key consideration relative to culturing methods. A performance-based criteria approach was selected in USEPA, 2000
(
72
)
as the preferred method through which individual laboratories could use unique culturing methods rather than requiring use of one culturing method.
5.3.3
This standard recommends the use of performance-based criteria to allow each laboratory to optimize culture methods and minimize effects of test organism health on the reliability and comparability of test results. See
Annex A1
and
Annex A2
for a listing of performance criteria for culturing or testing.