Pesticides in Stream Sediment and Aquatic Biota Distribution, Trends, And Governing Factors - Chapter 6 pdf

CHAPTER 6 Analysis Of Key Topics—Environmental Significance Because hydrophobic pesticides tend to associate with particulates and organic matter, they may be found in bed sediment and aquatic biota even when they are not detectable in water samples from the same hydrologic system. Thus, their detection in bed sediment and aquatic biota serves as an indicator that these compounds are present as contaminants in the hydrologic system. Clearly, the monitoring studies reviewed (Tables 2.1 and 2.2) indicate that many pesticides are frequently found in these media in rivers and streams of the United States. Yet, what is the significance of these residues to biota that live in or are dependent on the hydrologic systems? As noted in Chapter 4, organisms in the water column and in sediment may be exposed to pesticides in the dissolved form, or in association with colloids or particulates, or by ingestion of contaminated food or particulates. Pesticide-contaminated fish may be consumed by both wildlife and humans, thus reintroducing the pesticide into the terrestrial environment. These exposures thus result in the potential for adverse effects on ecosystems and human health. The potential effects of hydrophobic pesticides on aquatic organisms and fish-eating wildlife, and on human health, are discussed in Sections 6.1 and 6.2, respectively. 6.1 EFFECTS OF PESTICIDE CONTAMINANTS ON AQUATIC ORGANISMS AND FISH-EATING WILDLIFE A review of the toxicity of organochlorine and other hydrophobic contaminants to fish, other aquatic organisms, and wildlife is beyond the scope of this book. The literature in this area is voluminous (e.g., U.S. Environmental Protection Agency, 1975; Eisler, 1985, 1990; Eisler and Jacknow, 1985; Murty, 1986a,b). For example, DDT has been shown to adversely affect a variety of organisms, from phytoplankton to fish-eating birds and mammals. In a report supporting its decision to ban DDT, U.S. Environmental Protection Agency (USEPA) reviewed the adverse effects of DDT on fish and wildlife known at that time (U.S. Environmental Protection Agency, 1975). This review documented effects on phytoplankton (reduced photosynthesis and growth rates), aquatic invertebrates (acute toxicity at microgram per liter levels, and reproductive failure and other sublethal effects at nanogram per liter levels), and fish (acute toxicity at microgram per liter levels, reproductive impairment, and sublethal effects including abnormal utilization of amino acids, inhibition of thyroid activity, and interference with temperature regime selection). © 1999 by CRC Press LLC Exposure of fish to DDT may compound stress due to thermal pollution by affecting temperature selection and increasing oxygen consumption. Secondary effects of DDT on higher trophic levels (such as starvation following acute kills of prey organisms) have been observed. The disruptive effects of DDT on birds (mortality, eggshell thinning, abnormal courtship and reproductive behavior, and reproductive failure) have been studied extensively. U.S. Environmental Protection Agency (1975) concludes that a clear-cut time relation existed between eggshell production, concomitant reproductive failures, and DDT use in the United States. The report also concludes that DDT had contributed to the reproductive impairment of a number of fish species in natural waters. Fish-eating mammals also were shown to accumulate high levels of DDT and metabolites from their diets. More recent studies have shown that DDT and metabolites can have estrogenic effects on animals (e.g., Denison and others, 1981; Fry and Toone, 1981; Fry and others, 1987; Bustos and others, 1988; Guillette and others, 1994). Most other organochlorine compounds also are very toxic to aquatic organisms. Mayer and Ellersieck (1986) compiled acute toxicity data for xenobiotics from tests performed at the Columbia National Fisheries Laboratory (then part of the U.S. Fish and Wildlife Service [FWS]) and its field laboratories between 1965–1984. These tests covered 410 chemicals and 66 species of aquatic organisms under a variety of test conditions. Acute toxicity data from this report (Mayer and Ellersieck, 1986) for all pesticides and transformation products detected in aquatic biota are summarized in Table 6.1. The range of acute toxicity values (48-hour EC 50 or 96-hour LC 50 ) are presented in Table 6.1 for the principal species tested (daphnids, rainbow trout, fathead minnow, and bluegill), as well as for stoneflies and other species that were sensitive to specific chemicals. In Table 6.1, no attempt was made to describe test conditions (such as static versus flow-through, pH, hardness, and temperature) or other test characteristics (such as life stage of the organism and pesticide formulation) that may affect toxicity. Chlordane, DDD, dieldrin, endrin, heptachlor, methoxychlor, and toxaphene were acutely toxic to aquatic organisms, including daphnids and rainbow trout, at the low microgram per liter level (Table 6.1). Endosulfan also was toxic to amphipod crustaceans ( Gammarus species) and several species of fish (including rainbow trout and channel catfish) in the microgram per liter range (Mayer and Ellersieck, 1986). Although aquatic organisms are fairly resistant to mirex in short-term toxicity tests (Eisler, 1985; Mayer and Ellersieck, 1986), delayed toxicity to mirex has been observed for fish and crustaceans (Eisler, 1985). Many organochlorine pesticides besides DDT can cause impaired reproduction and other sublethal effects at low concentrations. Examples include toxaphene (Eisler and Jacknow, 1985), mirex (Eisler, 1985), chlordane, and dieldrin (Johnson, 1973; Thomas and Colborn, 1992). The toxicity of pesticide transformation products to aquatic organisms was reviewed by Day (1991). Transformation products may have lesser, greater, or comparable toxicity relative to the parent compound, depending on the pesticide, type of organisms tested, and even test condi- tions. The organochlorine insecticides tend to be persistent in the environment, but they do degrade (albeit slowly) under natural conditions to transformation products that are more stable than the parent compound (Sections 4.2.3 and 4.3.3). Some of these transformation products appear to be less toxic than the parent compound (e.g., DDD versus DDT), whereas others appear to have comparable or even greater toxicity (e.g., dieldrin versus aldrin), as shown in Table 6.1. Some metabolites of organophosphate, carbamate, and pyrethroid insecticides may be more toxic than the parent compound to some organisms. As discussed in Section 4.3.3, when a parent compound is biotransformed to a more toxic metabolite, the process is referred to as © 1999 by CRC Press LLC “metabolic activation.” The oxidation of the organophosphate insecticide parathion to paraoxon is a classic example of metabolic activation. For many herbicides, transformation products tend to be less toxic than the parent compound (Day, 1991). A number of guidelines have been developed that indicate threshold concentrations above which pesticide levels may adversely affect aquatic organisms or wildlife. In the discussion below, these guidelines will be used to assess the potential for biological effects in United States rivers on the basis of the maximum pesticide concentrations reported by the monitoring studies reviewed in this book. The fraction of studies in which these guidelines are exceeded provides some measure of the potential for biological effects in study areas where pesticide residues were detected. As used in this book, the term “guidelines” refers to threshold values that have no regulatory status but are issued in an advisory capacity. The issuing agency may use a different term to describe a given set of guidelines (such as criteria, advisories, guidance, or recommendations). For the most part, the guidelines used in this book were established on the basis of acute and chronic toxicity to aquatic organisms and wildlife. Except for some sediment guidelines (which also include field-based measures of biological effects), most of the guidelines used were based on the results of single-species toxicity tests conducted in the laboratory. Some additional toxicity-related issues (effects of chemical mixtures and potential endocrine- disrupting effects of pesticides) are briefly discussed in Section 6.1.4. Exposure of an aquatic organism to a pesticide in a hydrologic system may occur via physical contact with the pesticide in the water column, bed sediment, or sediment pore water, and by ingestion of contaminated water, food, or particulates. In the following discussion, potential effects are addressed separately for organisms exposed via the water column (Section 6.1.1), benthic organisms exposed via sediment (Section 6.1.2), and wildlife that consume contaminated aquatic biota (Section 6.1.3). 6.1.1 TOXICITY TO ORGANISMS IN THE WATER COLUMN USEPA water-quality criteria for the protection of aquatic organisms were designed to protect aquatic life from adverse effects of toxic pollutants in hydrologic systems (Nowell and Resek, 1994). These criteria are expressed on a water concentration basis. However, they can be used in conjunction with fish bioconcentration factors (BCF) to estimate pesticide concentrations in fish tissue that may be associated with potential biological effects. Additional information on potential biological effects of pesticide residues in fish can be gained by looking at fish kills and the incidence of fish diseases in association with chemical contaminant residues. Selected studies relating to these topics are discussed below. USEPA’s Water-Quality Criteria for Protection of Aquatic Organisms Ambient water-quality criteria were issued by USEPA for priority pollutants (pollutants designated as toxic under the Clean Water Act), in accordance with USEPA’s mandate under Section 304(a) of that Act. This list of priority pollutants includes a number of pesticides, including most of the organochlorine insecticides (Code of Federal Regulations, Volume 40, Part 423, Appendix A). Water-quality criteria for the protection of aquatic organisms (also called “aquatic life criteria”) for most of the priority pollutant pesticides were issued in 1980 (U.S. Environmental Protection Agency, 1980a–h). However, aquatic life criteria for a few pesticides © 1999 by CRC Press LLC Pesticides Detected in Aquatic Biota (from Tables 2.1, 2.2) Total Number of Toxicity Tests Daphnids 1 Stoneflies 2 Rainbow Trout Number of Tests 48-Hour EC 50 ( µ g/L) Number of Tests 96-Hour LC 50 ( µ g/L) Number of Tests 96-Hour LC 50 ( µ g/L) Aldrin 26 3 23–32 1 1.3 6 2.6–14.3 Carbaryl 136 5 5.6–11 1 5.6 20 <320–3,500 Carbofuran 15 0 — 0 — 2 380–600 Chlordane 56 3 20–29 1 15 23 2.9–59 Chlorpyrifos 23 0 — 2 0.57–10 4 <1–51 D, 2,4- 21 0 — 0 — 1 110,000 Dacthal (DCPA) 9 4 27,000–>10 5 0—0— DDD 21 5 3.2–9.1 1 380 2 70 DDE 3 0 — 0 — 1 32 DDT 85 4 0.36–4.7 4 1.2–7 7 4.1–11.4 Diazinon 10 3 0.8–1.8 1 25 1 90 Dicofol 8 0 — 1 650 1 ( 3 ) Dieldrin 37 3 190–250 3 0.5–0.58 6 1.2–2.3 Endosulfan 10 0 — 1 2.3 4 1.1–2.9 Endrin 53 6 4.2–74 3 0.076–0.54 6 0.74–2.4 Fenvalerate 29 1 2.1 0 — 11 0.32–1.7 Heptachlor 31 3 42–80 3 0.9–2.8 6 7.0–43 Heptachlor Epoxide 20 —0—120 Hexachloro- benzene 12 0 —0—0— Kepone 14 1 260 0 — 2 29–30 Lindane 45 3 460–880 2 1.0–4.5 5 18–41 Methoxychlor 146 3 0.78–5.6 3 1.4–25 10 11–62 Methyl parathion 31 3 0.14–0.37 0 — 2 2,750–3,700 Mirex 13 3 >100–>1,000 0 — 2 >10 5 Nitrofen 1 0 — 0 — 0 — Table 6.1. Acute aquatic toxicity of pesticides detected in aquatic biota [Pesticides listed are those that were detected in aquatic biota by one or more monitoring studies listed in Tables 2.1 and 2.2. The range of acute toxicity values (48-h EC 50 or 96-h LC 50 ), in micrograms per liter, are listed. Total number of toxicity tests: the total number of toxicity tests, for all test species, listed in Mayer and Ellersieck (1986). Number of tests: the number of toxicity tests listed for a given species. Other most sensitive species: If the most sensitive test species is some other species than daphnids, stoneflies, rainbow trout, fathead minnow, or bluegill, then this species is specified and the number of tests and range in toxicity values are listed. Blank cell indicates that no other species tested were more sensitive than the species listed in previous columns of the table (scientific names included only if common name is general). Abbreviations and symbols: EC 50 , median effective concentration (usually refers to immobilization); h, hour; LC 50 , median lethal concentration; PCA, pentachloroanisole; PCNB, pentachloronitrobenzene; µ g/L, microgram per liter; —, no data. Compiled from Mayer and Ellersieck (1986)] © 1999 by CRC Press LLC Pesticides Detected in Aquatic Biota (from Tables 2.1, 2.2) Fathead Minnow Bluegill Other Most Sensitive Species Number of Tests 96-Hour LC 50 ( µ g/L) Number of Tests 96-Hour LC 50 ( µ g/L) Species Number of Tests 96-Hour LC 50 ( µ g/L) Aldrin 1 8.2 6 5.6–12 Carbaryl 3 7,700–14,600 14 1,800–39,000 Isogenus sp. 6 2.8–12 Carbofuran 3 872–1,990 2 88–240 Chlordane 2 56–115 3 57–128 Channel catfish 5 0.8–230 Chlorpyrifos 0 — 5 1.7–4.2 Gammarus lacustris 1 0.11 D, 2,4- 1 133,000 1 180,000 Cutthroat trout 12 37,000– 172,000 Dacthal (DCPA) 0 — 1 >100 G . pseudolimnaeus 2 26.2–>100 DDD 1 4,400 1 42 G . fasciatus 2 0.6–0.9 DDE 0 — 1 240 DDT 3 9.9–13.2 7 1.6–8.6 Orconectes nais 7 0.18–100 Diazinon 0 — 1 168 G . fasciatus 1 0.2 Dicofol 0 — 1 520 Cutthroat trout 2 53–158 Dieldrin 1 3.8 8 3.1–18 Endosulfan 1 1.5 1 1.2 Endrin 2 0.24–1.8 7 0.19–0.73 Fenvalerate 2 2.15–2.35 11 0.42–1.35 G . pseudolimnaeus 1 0.032 Heptachlor 1 23 3 13–17 O. nais 1 0.5 Heptachlor Epoxide 0 — 1 5.3 Hexachloro- benzene 1 >10,000 2 >1,000–12,000 Channel catfish 3 7,000–>10 6 Kepone 2 340–420 1 72 Lindane 4 67–87 6 25–68 Methoxychlor 1 31 5 25–79 Methyl parathion 3 7,200–9,960 3 1,000–4,380 Mirex 1 >10 5 2 >10 5 Nitrofen 0 — 0 — G . fasciatus 1 3,100 Table 6.1. Acute aquatic toxicity of pesticides detected in aquatic biota— Continued © 1999 by CRC Press LLC (toxaphene, chlorpyrifos, pentachlorophenol, and parathion) were issued or revised in 1986 (U.S. Environmental Protection Agency, 1986b–e). USEPA aquatic-life criteria are national numerical criteria designed to prevent unacceptable long-term and short-term effects on aquatic organisms in rivers, streams, lakes, reservoirs, oceans, and estuaries. Separate criteria were determined for freshwater and saltwater organisms and for acute (short-term) and chronic (long-term) exposures. Criteria were established on the basis of toxicity tests with at least one species of aquatic animal in at least eight families (Stephan and others, 1985; U.S. Environmental Protection Agency, 1986f). Criteria values were established to protect 95 percent of the genera tested (Stephan and others, 1985), which suggests that effects on fewer than 5 percent of organisms would not be unacceptable. Also, it is assumed that an aquatic ecosystem can recover as long as the average concentration over a prescribed period (1 hour for acute criteria and 4 days for chronic criteria) does not exceed the applicable criterion more than once every 3 years on average. USEPA water- quality criteria for pesticides are expressed as pesticide concentrations in whole water, so they cannot be directly compared with pesticide residues in sediment or aquatic biota (Nowell and Resek, 1994). In their review of pesticides in surface waters of the United States, Larson and others (1997) compared ambient pesticide concentrations in surface waters (from national, multistate, state, and local monitoring studies) with USEPA water-quality criteria. Every one of the organochlorine insecticides targeted in the surface water studies reviewed by Larson and others 1 Daphnia magna, D. pulex , or Simocephalus serrulatus. 2 Claasenia sabulosa, Pteronarcys californica, or Pteronarcella badia. 3 Not measured. Table 6.1. Acute aquatic toxicity of pesticides detected in aquatic biota— Continued Pesticides Detected in Aquatic Biota (from Tables 2.1, 2.2) Total Number of Toxicity Tests Daphnids 1 Stoneflies 2 Rainbow Trout Number of Tests 48-Hour EC 50 ( µ g/L) Number of Tests 96-Hour LC 50 ( µ g/L) Number of Tests 96-Hour LC 50 ( µ g/L) Oxadiazon 0 — — — — — — Oxychlordane 0 — — — — — — Parathion 47 4 0.37–0.6 3 1.5–5.4 4 780–1,430 PCA 0 — — — — — — PCNB 0 — — — — — — Pentachloro- phenol 15 2 240–410 0 — 4 34–121 Permethrin 29 1 1.26 0 — 10 2.9–8.2 Photomirex 0 — — — — — — Strobane 0 — — — — — Tetradifon 5 0 — 0 — 2 1,200–1,350 Toxaphene 89 4 10–19 3 1.3–2.3 7 1.8–12 Trifluralin 62 3 560–900 1 2,800 25 22–1,600 Xytron 0 — — — — — — © 1999 by CRC Press LLC (1997) exceeded the applicable aquatic-life criterion (if one had been established) in one or more surface water studies. The number of studies in which criteria were exceeded was probably an underestimate, because detection limits were frequently higher than the USEPA chronic criteria (Larson and others, 1997). However, many contaminant monitoring studies do not analyze for organochlorine insecti- cides in water, but instead rely on bed sediment and aquatic biota sampling to determine whether these hydrophobic contaminants are present in the hydrologic system. Both national trends (Section 3.4.1) and local trends (Larson and others, 1997) in organochlorine contamination are more easily seen in fish or sediment than in water. Also, because analytical detection limits in water are commonly at or above chronic water-quality criteria for the organochlorine pesticides (Larson and others, 1997), detection of organochlorine compounds in surface waters at biologically significant levels may require special monitoring techniques such as large-volume samplers. For organochlorine compounds, the use of water-column concentrations to assess their aquatic toxicity is complicated by the fact that a significant fraction of these hydrophobic compounds in whole water may be associated with dissolved organic carbon or suspended particles in the water, thereby reducing their bioavailability to organisms in the water column (Landrum and others, 1985; Knezovich and others, 1987). Existing USEPA water-quality criteria for pesticides in surface water were derived on the basis of total concentrations of contaminant in Pesticides Detected in Aquatic Biota (from Tables 2.1, 2.2) Fathead Minnow Bluegill Other Most Sensitive Species Number of Tests 96-Hour LC 50 ( µ g/L) Number of Tests 96-Hour LC 50 ( µ g/L) Species Number of Tests 96-Hour LC 50 ( µ g/L) Oxadiazon — — — — Oxychlordane — — — — Parathion 2 2,090–2,350 7 18–400 O. nais 2 0.04–15 PCA — — — — PCNB — — — — Pentachloro- phenol 1 205 2 32–215 Chinook salmon 3 31–68 Permethrin 2 5.7 10 4.5–13 G. pseudolimnaeus 1 0.17 Photomirex — — — — Strobane — — — — Tetradifon 0 — 1 880 G. fasciatus 1 111 Toxaphene 10 5.6–23 13 2.4–18 Channel catfish 26 0.82–13.1 Trifluralin 3 105–160 17 8.4–400 Xytron — — — — Table 6.1. Acute aquatic toxicity of pesticides detected in aquatic biota— Continued © 1999 by CRC Press LLC water, rather than on the dissolved or bioavailable fractions; at the time the criteria were developed, there was no attempt to make such a distinction (Nowell and Resek, 1994). Detection of organochlorine insecticides for aquatic biota or bed sediment in a hydrologic system indicates the presence of these contaminants in that system. However, it is difficult to assess the biological significance of this contamination to fish and other aquatic organisms in the system. No guidelines exist that relate contaminant concentrations in fish tissues, for example, to toxicity to the fish. In theory, chronic aquatic-life criteria (which indicate a threshold concentration in water above which chronic toxicity may occur) can be used to estimate contaminant concentrations in fish tissues that may be associated with biological effects. This extrapolation would require that equilibrium between the pesticide concentrations in fish and in ambient water be assumed. At equilibrium, the fish tissue concentration (FTC) corresponding to the chronic aquatic-life criterion would be calculated as follows: FTC = WQC chronic ϫ (BCF) (6.1) where the FTC is in units of µ g/kg fish (wet weight), WQC chronic is the USEPA chronic water- quality criterion for the protection of aquatic organisms (in µ g/L), and BCF is the fish bioconcentration factor (in L/kg fish). Pesticide concentrations in fish and the surrounding water are unlikely to be in thermodynamic equilibrium in the environment, given factors such as the mobility, metabolism, and growth of fish and the dynamic nature of water flow, pesticide input, and pesticide degradation. Maintenance of steady-state concentrations (discussed in Section 5.2.1) would be a more realistic simplifying assumption. Despite the crudeness of the FTC approach, it gives some indication of which pesticide concentrations in fish tissue may be associated with potential biological effects. There are two potential problems with the FTC approach described in equation 6.1 that need to be addressed. First, this extrapolation is very sensitive to the BCF values used. BCF values can be calculated or determined experimentally, and they frequently vary depending on the species and test conditions (Howard, 1991; U.S. Environmental Protection Agency, 1992b). Also, laboratory-measured BCF values for organochlorine compounds are frequently lower than field-measured bioaccumulation factors (BAF) (Section 5.2.4, see subsection on Bioaccumulation Factors). The higher the BCF value used, the higher the corresponding FTC, and the less likely that the FTC will be exceeded by measured concentrations in fish. Second, the chronic aquatic-life criterion must be a threshold concentration for chronic toxicity to organisms in the water column. Although this sounds self-evident, this is not necessarily the case for all priority pollutants. For some priority pollutants (including DDT and chlordane), the chronic aquatic-life criterion is actually lower than the threshold for chronic toxicity. This happens because the chronic aquatic-life criterion is designed to protect aquatic organisms and their uses. Specifically, the USEPA guidelines for deriving water-quality criteria for the protection of aquatic organisms (Stephan and others, 1985) dictate that the chronic aquatic-life criterion be the lowest of three values: the final chronic value (which measures chronic toxicity to aquatic animals), the final plant value (which measures toxicity to aquatic plants), and the final residue value (which protects fish-eating wildlife and the marketability of fish). The rationale for this is that, if ambient concentrations do not exceed the lowest of these © 1999 by CRC Press LLC three values, then all of the corresponding uses will be protected. For several organochlorine insecticides (including DDT, chlordane, and dieldrin), the final residue value (generally the Food and Drug Administration [FDA] action level; see Section 6.2.3) was the lowest of the three values, so it was selected as the chronic aquatic-life criterion. For these organochlorine insecticides, the final chronic value (rather than the chronic aquatic life criterion itself) should be used to estimate the FTC. In Table 6.2, FTC values were extrapolated from final chronic values ( µ g/L) for several pesticides: chlordane, chlorpyrifos, dieldrin, endosulfan, endrin, hexachlorobenzene, lindane, and toxaphene. With one exception, all final chronic values in Table 6.2 are from water-quality criteria documents (U.S. Environmental Protection Agency, 1980b,c,e,f,h; 1986b,e). The exception is that of dieldrin, which is from the sediment quality criteria document (U.S. Environmental Protection Agency, 1993a), in which acute and chronic toxicity data were updated from the original water-quality criteria document for aldrin and dieldrin (U.S. Environmental Protection Agency, 1980a), and the final chronic value revised. For consistency, BCF values (normalized to 3 percent lipids, which is the weighted average for consumed fish) were taken from the same references (U.S. Environmental Protection Agency, 1980a,b,c,e,f,h,i) when available. Although these BCF values are not the most recent estimates, they were geometric means of values available at the time and they form a consistent data set. The BCF value for chlorpyrifos was taken from U.S. Environmental Protection Agency (1992b). Several pesticides that have been detected in bed sediment and aquatic biota are missing from Table 6.2 because data were insufficient to compute FTC values: DDT, heptachlor, heptachlor epoxide, pentachlorophenol, and parathion. For DDT, heptachlor, and heptachlor epoxide, there were insufficient aquatic toxicity data to determine final chronic values at the time the water-quality criteria were developed (U.S. Environmental Protection Agency, 1980d,g). For pentachloro- phenol, the freshwater final chronic value in the water-quality criteria document is pH dependent (U.S. Environmental Protection Agency, 1986d). For parathion, no BCF value was available. Pesticides in Whole Fish—Analysis of Potential Fish Toxicity The FTC values described in the preceding section were compared with maximum concentrations of pesticides in whole fish that were reported by individual monitoring studies (Tables 2.1 and 2.2). Even when only recently published (1984–1994) monitoring studies were considered, the FTCs of several of these pesticides were exceeded by the maximum concentrations in whole fish reported by one or more studies (Table 6.2): 11 percent of studies for dieldrin (7 of the 64 studies measuring dieldrin in whole fish), 25 percent of studies for total endosulfan (1 of 4 studies), 14 percent of studies for endrin (2 of 14 studies), 17 percent of studies for lindane (6 of 35 studies), and 100 percent of studies for toxaphene (15 of 15 studies). No studies reported maximum concentrations that exceeded the extrapolated FTCs for total chlordane (out of 18 studies that measured total chlordane in whole fish), chlorpyrifos (out of 2 studies), or hexachlorobenzene (out of 44 studies). For studies in which the FTC was exceeded, this indicates potential for toxicity to fish at the most contaminated site in each study. Because only maximum concentrations have been compared with FTCs, Table 6.2 does not indicate what fraction of sites or samples exceeded the FTC in each study. © 1999 by CRC Press LLC Table 6.2. Potential chronic toxicity to aquatic biota in studies that monitored pesticides in whole fish [Development of FTC guidelines: The USEPA final chronic value ( µ g/L) and BCF at 3 percent lipid (L/kg fish) are multiplied to give the fish tissue concentration ( µ g/kg fish). Monitoring studies that reported concentrations in whole fish: Data are based on monitoring studies in Tables 2.1 and 2.2 that (1) were published during 1984–1994 and (2) reported concentrations in whole fish. The total number of studies, the range in maximum concentrations reported in these studies, the number of studies for which the maximum concentration exceeded the applicable FTC, and the percentage of studies for which the maximum concentration exceeded the applicable FTC. Abbreviations: BCF, bioconcentration factor; C max , the maximum concentration reported in a study; FTC, fish tissue concentration; nd, not detected; kg, kilogram; L, liter; µ g, microgram] Pesticide Development of FTC guidelines Recently Published (1984–1994) Monitoring Studies—Whole Fish Final Chronic Value ( µ g/L) BCF at 3 Percent Lipid (L/kg Fish) FTC ( µ g/kg Fish) Total Number of Studies Range in C max ( µ g/kg) Number of Studies with C max that Exceeded FTC Percentage of Studies with C max that Exceeded FTC Chlordane 0.17 14,100 2,400 18 nd–870 0 0 Chlorpyrifos 0.041 470 19 2 nd 0 0 Dieldrin 0.0625 4,670 292 64 nd–5,680 7 11 Endosulfan 0.056 270 15 4 nd–170 1 25 Endrin 0.061 3,970 242 14 nd–2,060 2 14 Hexachlorobenzene 3.68 8,690 32,000 45 nd–27,000 0 0 Lindane 0.08 130 10 35 nd–120 6 17 Toxaphene 0.013 13,100 170 15 nd–280,330 15 100 © 1999 by CRC Press LLC © 1999 by CRC Press LLC [...]... involves compiling chemical and biological data into an effects data set and a no-effects data set for each chemical; listing the studies in each data set in ascending order by chemical concentration in sediment; and determining a TEL and PEL The TEL and PEL are defined exactly as described in the preceding subsection on the Florida guidelines Then, the Canadian interim sediment quality guideline (ISQG)... in a number of severe fish kills (Madhun and Freed, 1990) Examples include the flushing of endrin and the fungicide nabam from a potato sprayer into the Mill River on Prince Edward’s Island, Canada, in 1 962 (Saunders, 1 969 ) and the accidental discharge of pesticides into the Rhine River in 1987 (Capel and others, 1988) A National Oceanic and Atmospheric Administration (NOAA) report evaluated over 3 ,60 0... pentachlorophenol Effects Range Values for Aquatic Sediment Long and coworkers (Long and Morgan, 1991; Long and others, 1995) compiled and evaluated data from the literature on contaminant concentrations in sediment and associated © 1999 by CRC Press LLC Table 6. 4 Sediment- quality guidelines and boundary values for pesticides in bed sediment Continued Screening Value L U NOAA NS&T4 Target Analytes L... (Mount and Pudnicki, 1 966 ) Forest spraying with DDT to control insects such as spruce budworm and black-headed budworm caused fish kills in the Yellowstone River system (Cope, 1 961 ), the Miramachi River in New Brunswick, Canada (Kerwill and Edwards, 1 967 ), and the forests of British Columbia (Crouter and Vernon, 1959) and Maine (Warner and Fenderson, 1 962 ) Thousands of fish were killed following DDT... plotted in Figures 6. 1 6. 5: dieldrin, total chlordane, and total DDT (the most commonly detected pesticides or pesticide groups); p,p′-DDE (the most abundant component of total DDT); and diazinon (as an example of a pesticide with insufficient guidelines to determine a Tier 1–2 boundary value) The results for these and other pesticides are discussed individually below Aldrin and Dieldrin There were no sediment. .. observed An example (dieldrin) is shown in Table 6. 5 By using multiple approaches to determine ERL and ERM values, the in uence of any single data point in setting these guidelines was minimized Long and Morgan (1991) referred to this as “establishing the preponderance of evidence.” For each chemical considered, the accuracy of the ERL and ERM guidelines was limited by the quantity and consistency of the...Fish Kills Attributed to Pesticides A number of fish kills that occurred during the 1950s and 1 960 s were attributed to organochlorine insecticides (Madhun and Freed, 1990) For example, it was estimated that 10 to 15 million fish were killed during 1 960 –1 963 in the Mississippi and Atchafalaya rivers and associated bayous in Louisiana The organochlorine insecticide endrin was singled out as a major cause... the available sediment quality guidelines for an individual sediment contaminant Note that the guidelines assembled and used by U.S Environmental Protection Agency (1997a) to analyze data in the National Sediment Inventory included both freshwater guidelines (such as USEPA’s proposed SQC) and saltwater guidelines (such as ERMs and ERLs from Long and others, 1995) Next, individual guidelines were labeled... maximum concentrations reported by individual monitoring studies in Tables 2.1 and 2.2 were compared with applicable sediment guidelines These sediment guidelines, as well as Tier 1–2 and Tier 2–3 boundary values, are listed in Table 6. 4 for individual pesticides and pesticide transformation products In the monitoring studies reviewed, pesticide concentrations in sediment generally were reported on... derivation is described in detail in Long and Morgan (1991) Long and coworkers (Long and Morgan, 1991; Long and others, 1995) screened studies using a variety of biological approaches, including equilibrium partitioning, spiked sediment bioassays, and several biological effects correlation methods (including AETs) For a given chemical, any individual study was included if both biological and sediment chemistry . — — 67 0 .67 —— Methoxychlor — — 1,900 19 —— Nonachlor, cis-—— — — —— Table 6. 4. Sediment- quality guidelines and boundary values for pesticides in bed sediment [For guidelines on a sediment- organic. monitoring studies do not analyze for organochlorine insecti- cides in water, but instead rely on bed sediment and aquatic biota sampling to determine whether these hydrophobic contaminants are. Table 6. 1. Acute aquatic toxicity of pesticides detected in aquatic biota [Pesticides listed are those that were detected in aquatic biota by one or more monitoring studies listed in Tables