P ART 5 Proposed Mercury Criteria, Concluding Remarks © 2006 by Taylor & Francis Group, LLC 271 C HAPTER 12 Proposed Mercury Criteria for Protection of Natural Resources and Human Health Proposed mercury criteria for the protection of representative crops, aquatic organisms, birds, and mammals are shown in Table 12.1, and for human health in Table 12.2. These criteria vary widely between nations and even between localities in the same nation. In almost every instance, these criteria are listed as concentrations of total mercury, with most, if not all, of the mercury present as an organomercury species. In some cases, recommended mercury criteria are routinely exceeded, as is the case for brown bears (Ursus arctos) in the Slovak Republic (Zilincar et al., 1992), and in Italian seafood products recommended for human consumption (Barghigiani and De Ranieri, 1992). 12.1 AGRICULTURAL CROPS Proposed mercury criteria for crop protection (Table 12.1) include < 0.2 µg/L in irrigation water, and < 0.2 to < 0.5 mg/kg DW in soils of several countries, although higher levels are allowable in cropland soils of New Jersey (< 1.0 mg/kg DW) and the Former Soviet Union (< 2.1 mg/kg DW). Sludge and other wastes applied to European soils should contain < 1.5 mg Hg/kg, but higher levels of < 10.0 to 25.0 mg Hg/kg are permissible in solid wastes applied to agricultural soils of Iowa, Maine, Vermont, and California (Table 12.1). 12.2 AQUATIC LIFE In 1980, the U.S. Environmental Protection Agency’s proposed mercury criteria for freshwater aquatic life protection were 0.00057 µg/L (24–h average), not to exceed 0.0017 µg/L at any time; these criteria seemed to afford a high degree of protection to freshwater biota, as judged by survival, bioconcentration, and biomagnification. Literature documented in USEPA (1980) showed that mercury concentrations in water of 0.1 to 2.0 µg/L were fatal to sensitive aquatic species and that concen- trations of 0.03 to 0.1 µg/L were associated with significant sublethal effects. The 1980 proposed freshwater criteria provided safety factors for acute toxicities of 175 to 3508 based on the 24-h average, and 58 to 1176 based on the maximum permissible concentration (Table 12.1). For protection against sublethal effects, these values were 53 to 175 based on the 24-h mean, and 18 to 59 based on the maximum permissible concentration (Table 12.1). However, more recent freshwater criteria of 0.012 µg/L, not to exceed 2.4 µg/L (Table 12.1; USEPA, 1985), dramatically reduce the level of protection afforded aquatic biota: safety factors for acute toxicities are now 8 to 167 based on the 96-h average, and only 0.04 to 0.8 based on the maximum permissible concentration. For © 2006 by Taylor & Francis Group, LLC © 2006 by Taylor & Francis Group, LLC 272 MERCURY HAZARDS TO LIVING ORGANISMS Table 12.1 Proposed Mercury Criteria for the Protection of Selected Natural Resources Resource and Other Variables Criterion or Effective Mercury Concentration Ref. a Crops Irrigation water, Brazil < 0.2 µ g/L 1 Land application of sludge and solid waste; maximum permissible concentration: Europe; soils with pH 6.0–7.0 < 1.0–< 1.5 mg/kg sludge 39 Iowa, Maine, Vermont 10.0 mg/kg waste 2 California 20.0 mg/kg waste 2 Vermont, sewage sludge: Loamy sand and sandy loam soils < 6.0 kg Hg/ha 39 Fine sandy loam, loam, and silt loam soils < 11.0 kg Hg/ha 39 Clay loam, clay, silty clay < 22.0 kg Hg/ha 39 Soils, Australia; urban areas < 1.0 mg/kg FW 45 Soils, Germany < 2.0 mg/kg dry weight (DW) 3 Soils, Canada, agricultural lands < 0.5 mg/kg DW 39 Soils, Finland: Recommended < 0.2 mg/kg DW 37 Maximum allowable < 5.0 mg/kg DW 37 Soils, Former Soviet Union < 2.1 mg/kg DW 39 Soils, Japan, contaminated > 3.0 mg/kg DW 39 Soils, Netherlands: Target < 0.3 mg/kg DW 45 Normal < 0.5 mg/kg DW 39 Moderate contamination: requires additional study > 2.0 mg/kg DW 39 Contaminated; immediate cleanup required > 10.0 mg/kg DW 39 Soils, New Jersey < 1.0 mg/kg DW 39 Aquatic Life Diet, piscivorous fishes < 100.0 µ g total mercury/kg fresh weight (FW) whole prey fish f 44 Freshwater: Total mercury < 0.00057 µ g/L, 24 h average; not to exceed 0.0017 µ g/L at any time 4 Total mercury < 0.1 µ g/L 5, 38 Total mercury; adverse effects expected with chronic exposure > 0.012 µ g/L 47 Inorganic mercury Adverse effects at > 0.23 µ g Hg 2+ /L 7 Methylmercury < 0.01 µ g/L 6 Total mercury < 0.012 µ g/L, 4-day average (not to be exceeded more than once every 3 years); < 2.4 µ g/L, 1-hour average (not to be exceeded more than once every 3 years) b 7 Inland surface waters, India < 10.0 µ g/L from point source discharge 8 Public water supply, Wisconsin < 0.079 µ g/L 2 Saltwater Total recoverable mercury < 0.025 µ g/L, 24-h average; not to exceed 3.7 µ g/L at any time g 4, 7 Saltwater < 0.025 µ g/L, 4-day average; < 2.1 µ g/L, 1 - hour average 7 Sediments: California: Low toxic effect > 0.15 mg/kg DW 9 Acceptable < 0.51 mg/kg DW 9 Bivalve molluscs, abnormal larvae > 0.51 mg/kg DW 9 Hazardous > 1.2–1.3 mg/kg DW 9 © 2006 by Taylor & Francis Group, LLC PROPOSED MERCURY CRITERIA 273 Table 12.1 (continued) Proposed Mercury Criteria for the Protection of Selected Natural Resources Resource and Other Variables Criterion or Effective Mercury Concentration Ref. a Canada, marine and freshwater: Safe < 0.14 mg/kg DW 6 Adverse effects expected > 2.0 mg/kg DW 9 Ecuador < 0.45 mg/kg DW 38 Great Lakes: Nonpolluted < 1.0 mg/kg DW 39 Heavily polluted > 1.0 mg/kg DW 39 Wisconsin sediment disposal into Great Lakes < 0.1 mg/kg DW 39 Ontario guideline for disposal of dredged sediments into lake < 0.3 mg/kg DW 39 Washington state, safe < 0.41 mg/kg DW 9 Tissue residues: Goldfish, Carassius auratus ; impaired egg production and spawning expected; gonad > 0.76 mg/kg FW 43 Rainbow trout, Oncorhynchus mykiss Lethal: Eggs > 70.0 µ g/kg FW 10 Muscle, adults > 10.0 mg/kg FW 10 Whole body 10.0–20.0 mg/kg FW 11 Adverse effects probable, whole body 1.0–5.0 mg/kg FW 11 Impaired spawning and reduced survival of early life stages expected; gonad 0.49 mg/kg FW 43 Brook trout, Salvelinus fontinalis ; whole body, nonlethal < 5.0 mg/kg FW 4,7 Various species of freshwater adult fishes; adverse effects expected: Brain: Toxic > 3.0 mg/kg FW 10 Potentially lethal > 7.0 mg/kg FW 10 Muscle: Toxic > 5.0–8.0 mg/kg FW 10 Lethal 10.0–20.0 mg/kg FW 10 Whole body: Adverse effects > 1.0 mg/kg FW 7 No observed effect < 3.0 mg/kg FW 10 Amphibians South African clawed frog, Xenopus laevis ; impaired gamete function and reduced early life survival expected; gonad > 0.48 mg/kg FW 43 Birds Tissue residues: Safe: Brain, muscle < 15.0 mg/kg FW 12 Feather < 5.0 mg/kg FW 12, 13 Kidney, seabirds < 30.0 mg/kg FW 14 Kidney, not seabirds < 20.0 mg/kg FW 12,1 4 Liver: Normal 1.0–10.0 mg/kg FW 15 Toxic to sensitive species > 5.0–6.0 mg/kg FW 15, 16 Hazardous, possibly fatal > 20.0 mg/kg FW 15, 17 Egg: Mallard, Anas platyrhynchos ; safe < 0.8–< 1.0 mg/kg FW 18, 19 Ring - necked pheasant, Phasianus colchicus ; safe 0.5–< 0.9 mg/kg FW 20,21 (continued) © 2006 by Taylor & Francis Group, LLC 274 MERCURY HAZARDS TO LIVING ORGANISMS Table 12.1 (continued) Proposed Mercury Criteria for the Protection of Selected Natural Resources Resource and Other Variables Criterion or Effective Mercury Concentration Ref. a Common tern, Sterna hirundo ; normal reproduction vs. reduced hatching and fledging success < 1.0 mg/kg FW vs. 2.0–4.7 mg/kg FW 21 Various species; safe < 0.5 to < 2.0 mg/kg FW 14, 22 Waterbirds; adverse effects 1.0 to 3.6 mg/kg FW 16 Feather, acceptable < 9.0 mg/kg FW 23 Methylmercury — poisoned: Brain 15.0–20.0 mg/kg FW 12 Liver 20.0–60.0 mg/kg FW 12 Kidney 20.0–60.0 mg/kg FW 12 Muscle 15.0–30.0 mg/kg FW 12 Diet, fish-eating birds < 20.0 µ g Hg/kg FW ration, as methylmercury 24 Diet, fish-eating birds < 100.0 µ g total Hg/kg FW in prey fish f 44 Diet, non fish-eating birds 50.0–< 100.0 µ g Hg/kg FW ration, as methylmercury 18, 25 Diet, loon < 300.0 µ g/kg FW ration c 26, 27 Diet < 1.0–< 3.0 mg/kg DW 14, 28 Daily intake < 640.0 µ g/kg body weight (BW) 20,29–31 Daily intake < 32.0 µ g/kg BW d 31 Mammals Daily intake < 250.0 µ g/kg BW 32 Diet; fish-eating mammals < 100.0 µ g Hg/kg FW ration, as methylmercury 24 Diet; fish-eating mammals < 100.0 µ g total Hg/kg FW whole prey fish f 44,50 Diet < 1.1 mg/kg FW ration 14 Diet; methylmercury poisoning of minks and otters > 1.0 mg/kg FW ration 40–42, 46 Diet; minks and otters; adverse effects > 0.12 to 1.4 mg total mercury/kg FW ration 51 Drinking water: Feral and domestic animal water supply, Wisconsin < 0.002 µ g/L 2 Terrestrial vertebrate wildlife < 0.0013 µ g/L e 31 Soils; terrestrial ecosystem protection; agricultural and residential land use vs. commercial and industrial use < 2.0 mg/kg DW vs. < 30.0 mg/kg DW 6 Tissue residues: Acceptable, most species: Kidney < 1.1 mg/kg FW 23 Liver, kidney < 30.0 mg/kg FW 14 Blood < 1.2 mg/kg FW 33 Brain < 1.5 mg/kg FW 33 Hair < 2.0 mg/kg FW 33 Acceptable; otters, Lutra spp.: Hair < 1.0 –< 5.0 mg/kg DW 48 Liver < 4.0 mg/kg FW 49 Mercury-poisoned minks and otters: Brain > 10.0 mg/kg FW 40–42, 46 Liver > 20.0–> 100.0 mg/kg FW 40–42, 46 Florida panther, Felis concolor coryi ; blood: Reproduction normal (1.46 kittens per female annually) < 250.0 µ g/kg FW 34 Reproduction inhibited (0.167 kittens per female annually) > 500.0 µ g/kg FW 34 European otter, Lutra lutra ; liver Normal < 4.0 mg/kg FW 35 Adverse sublethal effects possible > 10.0 mg/kg FW 35 © 2006 by Taylor & Francis Group, LLC PROPOSED MERCURY CRITERIA 275 protection against sublethal effects, these values were 2 to 8 based on the 4 - day average, and only 0.01 to 0.04 based on the maximum permissible concentration, or essentially no significant pro- tection. The proposed saltwater criteria of USEPA (1980) for mercury and marine life were unsatisfactory. Proposed saltwater values of 0.025 µ g/L (24-h average), not to exceed 3.7 µ g/L at any time (Table 12.1), provided safety factors of 4 to 8O against acute toxicity (based on 24-h average), but less than 0.5 based on the maximum permissible level. For protection against sublethal damage effects, the safety factors computed were 1.2 to 4 (based on 24-h average) and less than 0.03 (based on maximum allowable concentration). The more recent saltwater criteria of 0.025 µ g/L, not to exceed 2.1 µ g/L (Table 12.1; USEPA, 1985), does not appear to offer a substantive increase in protection to marine life, when compared to criteria proposed 5 years earlier (USEPA, 1980). It seems that some downward modification is needed in the proposed mercury saltwater criteria if marine and estuarine biota are to be provided even minimal protection. The significance of elevated mercury residues in tissues of aquatic organisms is not fully understood. Induction of liver metallothioneins and increased translatability of MRNA are bio- chemical indicators of the response of fish to mercury exposure (Angelow and Nicholls, 1991; Schlenk et al., 1995), and more research is recommended on this and other indicators of mercury stress. Concentrations exceeding 1.0 mg Hg/kg fresh weight can occur in various tissues of selected species of fish and aquatic mammals eaten by humans. But it would be incorrect to assume that aquatic food chains — especially marine food chains — incorporate mercury exclusively from anthropogenic activities (Barber et al., 1984). Some organisms, however, do contain mercury tissue residues associated with known adverse effects to the organism and its predators. Thus, whole body residues of 5.0 to 7.0 mg Hg/kg fresh weight in brook trout eventually proved fatal to that species (USEPA, 1980). To protect sensitive species of mammals and birds that regularly consume fish and Table 12.1 (continued) Proposed Mercury Criteria for the Protection of Selected Natural Resources Resource and Other Variables Criterion or Effective Mercury Concentration Ref. a Wildlife protection, Slovak Republic: Fat< 1.0 µ g/kg FW 36 Muscle < 50.0 µ g/kg FW 36 Liver, kidney < 100.0 µ g/kg FW 36 a Reference: 1, Palheta and Taylor, 1995; 2, U.S. Public Health Service (USPHS), 1994; 3, Zumbroich, 1997; 4, U.S. Environmental Protection Agency (USEPA), 1980; 5, Dave and Xiu, 1991; 6, Gaudet et al., 1995; 7, USEPA, 1985; 8, Abbasi and Soni, 1983; 9, Gillis et al., 1993; 10, Wiener and Spry, 1996; 11, Niimi and Kissoon, 1994; 12, Heinz, 1996; 13, U.S. National Academy of Sciences (USNAS), 1978; 14, Thompson, 1996; 15, Wood et al., 1996; 16, Zillioux et al., 1993; 17, Littrell, 1991; 18, Heinz, 1979; 19, Heinz and Hoffman, 2003; 20, Spann et al., 1972; 21, Mora, 1996; 22, Fimreite, 1979; 23, Beyer et al., 1997; 24, Yeardley et al., 1998; 25, March et al., 1983; 26, Scheuhammer et al., 1998; 27, Gariboldi et al., 1998; 28, Scheuhammer, 1988; 29, Mullins et al., 1977; 30, McEwen et al., 1973; 31, Wolfe and Norman, 1998; 32, Ramprashad and Ronald, 1977; 33, Suzuki, 1979; 34, Roelke et al., 1991; 35, Mason and Madsen, 1992; 36, Zilincar et al., 1992; 37, Peltola and Astrom, 2003; 38, Tarras–Wahlberg et al., 2000; 39, Beyer, 1990; 40, Aulerich et al., 1974; 41, Dansereau et al., 1999; 42, Wren et al., 1987a; 43, Birge et al., 2000; 44, Atkeson et al., 2003; 45, Zarcinas et al., 2004a; 46, Wren et al., 1987b; 47, USEPA, 1992; 48, Sheffy and St. Amant, 1982; 49, Wren, 1986; 50, Fonseca et al., 2005; 51, Halbrook et al., 1994. b All mercury that passes through a 0.45-micromillimeter membrane filter after the sample is acidified to pH 1.5 to 2.0 with nitric acid. Derived from bioconcentration factor of 81,700 for methylmercury and the fathead minnow, Pimephales promelas (USEPA, 1985). c Reproduction declined in loons, Gavia immer , when mercury in prey exceeded 300.0 µ g total mercury/kg FW. d No observed adverse effect level with uncertainty factor of 20. e Based on food chain biomagnification in aquatic webs. f Provisional U.S. Fish and Wildlife Service standard for protection of fish-eating wildlife and animals that feed on them. Also considered safe for propagation and maintenance of healthy well-balanced populations of fish and other wildlife (Atkeson et al., 2003). g Based on bioconcentration factor of 40,000 for methylmercury and the American oyster, Crassostrea virginica (USEPA, 1985). 276 MERCURY HAZARDS TO LIVING ORGANISMS other aquatic organisms, total mercury concentrations in these food items should probably not exceed 100.0 µg/kg for avian protection, or 1100.0 µg/kg for small mammals (Table 12.1). Since long-lived, slow-growing, high-trophic-position aquatic organisms usually contain the highest tissue mercury residues (Eisler, 1981, 2000), some fisheries managers have proposed a legal maximum limit based on fish length or body weight (Lyle, 1984; Chvojka, 1988), or alternatively, constraining the mean mercury concentration of the entire catch to a nominated level. In the Australian shark fishery, for example, implementation of a maximum length restriction (to a designated level of 500.0 µg Hg/kg), would result in retention of less than half of the present catch of seven species (Lyle, 1984). Also in Australia, a maximum total length of 92 cm is proposed for the taking of yellowtail kingfish (Seriola grandis) and would effectively remove 23.0% of the total weight of the catch and 9.0% of the numbers (Chvojka 1988). If the total length of the yellowtail kingfish is reduced to 73 cm, a length that ensures that almost all fish contained < 500.0 µg Hg/kg FW muscle, this would preclude 59.0% by weight and 30.0% by numbers (Chvojka, 1988). Other strategies to control mercury burdens in predatory fishes include control of forage fish, overfishing, and various chemical treatments. In lakes with pelagic forage fish, there is less than a 5.0% probability of finding elevated mercury levels in muscle of lake trout less than 30 cm in total length vs. 45 cm in lakes where pelagic forage fish were absent. In the case of lake trout lakes with no pelagic forage fish, every effort should be made to avoid their introduction (Futter, 1994). Over- fishing of top-level predators is recommended as a means of lowering methylmercury levels in certain types of lakes, and is attributed to the more rapid growth of the predators and by changes in the dietary intake of methylmercury (Verta, 1990). Treatment of lakes with selenium compounds is one of the few known methods of lowering the mercury content of fish muscle to < 1.0 mg Hg/kg FW (Paulsson and Lundbergh, 1989). Treatments that have achieved partial success in reducing mercury content in fish tissues include liming of lakes, wetlands, and drainage areas (Lindqvist et al., 1991). More research is needed on mercury protectants because several are known to cause substantial reductions in tissue mercury concentrations in fishes and plants (Siegel et al., 1991). Thiamine and various group VI derivatives, including sulfur, selenium, and tellurium compounds, protect against organomercury poisoning by their antagonistic effects; thiamine was the most effective of the derivatives against the widest spectrum of organisms and test systems (Siegel et al., 1991). More research is also needed on mercury removal technology. In the Florida Everglades, for example, using prototype wetlands of 1545 ha, removal of agricultural nutrients from stormwater reduced total mercury and methylmercury concentrations in water by as much as 70.0% in the first 2 years of operation. Moreover, total mercury concentrations in largemouth bass were about 0.1 mg Hg/kg FW muscle throughout the project site vs. 0.5 mg Hg/kg FW in adjacent areas (Miles and Fink, 1998). 12.3 BIRDS Tissue residues of mercury, as methylmercury, considered harmful to adult birds ranged from 8.0 mg/kg FW in brain to 15.0 in muscle to 20.0 mg/kg FW in liver and kidney (Heinz, 1996). Among sensitive avian species, adverse effects, mainly on reproduction, have been reported at total mercury concentrations (in mg/kg fresh weight) of 5.0 in feather, 0.9 in egg, 0.05 to 0.1 in diet, and daily administered doses of 0.64 mg/kg body weight (Table 12.1; Eisler, 2000). The proposed mercury concentration to protect sensitive species of birds that regularly consume fish and aquatic invertebrates is < 0.1 mg/kg FW in these food items (Eisler, 2000; Table 12.1). Although low mercury concentrations (e.g., 0.05 mg/kg in the diets of domestic chickens) sometimes produced no adverse effects on chickens, the tissue residues of mercury were sufficiently elevated to pose a hazard to human consumers (March et al., 1983). In contrast, with eggs of the bald eagle containing 0.15 mg Hg/kg FW and low hatch, it is probable that other contaminants © 2006 by Taylor & Francis Group, LLC PROPOSED MERCURY CRITERIA 277 present — especially organochlorine compounds — had a greater effect on hatchability than did mercury (Wiemeyer et al., 1984). 12.4 MAMMALS Mammals, such as the domestic cat and the harp seal, showed birth defects, histopathology, and elevated tissue residues at doses of 250.0 µg Hg/kg body weight daily (Table 12.1). Tissue residues of mercury, as methylmercury, considered harmful to adult inland mammals ranged between 8.0 mg/kg FW in brain, 15.0 in muscle, and 20.0 mg/kg FW in liver and kidney (Heinz, 1996). Mink fed dietary levels of 1.1 mg Hg/kg had signs of mercury poisoning; mercury residues in mink brain at this dietary level ranged from 7.1 to 9.3 mg/kg (Kucera, 1983). Tissue residues in kidney, blood, brain, and hair in excess of 1.1 mg Hg/kg in nonhuman mammals are usually considered presumptive evidence of significant mercury contamination (Table 12.1). To protect sensitive species of small mammals that regularly consume fish and other aquatic organisms, total mercury concen- trations in these food items should probably not exceed 100.0 µg total mercury/kg FW (Eisler, 2000; Table 12.1). For most species of mammals, recommended mercury criteria include daily intake of less than 250.0 µg total mercury/kg body weight; diets that contain less than 1.1 mg total mercury/kg FW; and for livestock, less than 0.002 µg total mercury/L in the drinking water supply (Table 12.1). Tissue mercury concentrations in sensitive mammals (in mg total mercury/kg FW) should probably not exceed 10.0 in liver, 2.0 in hair, 1.5 in brain, and 0.5 in blood (Table 12.1). 12.5 HUMAN HEALTH Proposed mercury criteria for the protection of human health are numerous and disparate (Table 12.2). Proposed mercury air criteria, for example, in the workplace range from < 10.0 µg/m 3 for organo- mercury compounds to < 50.0 µg/m 3 for elemental mercury vapor; however, much lower criteria are proposed by Texas (< 0.05 µg/m 3 for 1 year), New York (< 0.167 µg/m 3 per year), and other jurisdictions (Table 12.2). Drinking water criteria for total mercury range between < 1.0 and < 2.0 µg/L (USPHS, 1994; Gemici, 2004), except for Brazil with < 0.2 µg/L (Palheta and Taylor, 1995). Current fish consumption recommendations are based on risk assessments for children and women of child-bearing age (Weil et al., 2005). Dietary criteria for mercury range between 10.0 and 1500.0 µg/kg FW, with lower values associated with seafoods, organomercurials, and preg- nancy. Accordingly, proposed mercury levels in fish and seafood should not exceed 250.0 µg/kg FW for expectant mothers, and 400.0 to 1000.0 µg/kg FW for adults worldwide (Table 12.2). It is again emphasized that total mercury concentrations exceeding 1.0 mg/kg fresh weight naturally occur in edible tissues of some species of fish and aquatic mammals regularly eaten by humans (Barber et al., 1984). Proposed tolerable weekly intakes range between < 3.3 and 5.0 µg/kg body weight (Table 12.2). Daily mercury intake for pregnant women should not exceed < 0.6 to 1.1 µg total mercury/kg body weight vs. 4.3 µg/kg BW for others (Clarkson, 1990). It has been suggested that humans can safely ingest up to 8.4 mg Hg/kg body weight daily (Birke et al., 1972; USPHS, 1994), but this requires verification. The minimum toxic intake for humans is estimated to range between 0.6 and 1.1 µg methylmercury/kg body weight daily (Clarkson, 1990). Recommended total mercury concentrations in human tissues include < 5.8 µg/L in blood, < 0.7 mg/kg whole body, and < 6.0 to 50.0 mg/kg in hair (Table 12.2). Methylmercury concentration in scalp hair during pregnancy is considered the most reliable indicator for predicting the probability of psychomotor retardation in the child. The U.S. Environ- mental Protection Agency has established a Reference Dose of 1.0 mg total Hg/kg DW in hair as indicative of mercury exposure. At this level, women of child-bearing age are advised to stop © 2006 by Taylor & Francis Group, LLC © 2006 by Taylor & Francis Group, LLC 278 MERCURY HAZARDS TO LIVING ORGANISMS Table 12.2 Proposed Mercury Criteria for the Protection of Human Health Variables Criterion or Effective Mercury Concentration Ref. a Air; Safe California < 0.00 µ g/m 3 1 North Dakota < 0.0005 µg/m 3 for 8 h 1 Kansas 0.0024 µg/m 3 annually 1 Montana < 0.008 µg/m 3 for 24 h 1 Texas < 0.05 µg/m 3 for 1 year 1 New York < 0.167 µg/m 3 per year 1 Connecticut 1.0 µg/m 3 for 1 h; < 1.0 µg/m 3 for 8 h 1 Arizona < 1.5 µg/m 3 for 1 h 1 Virginia < 1.7 µg/m 3 for 24 h 1 General population; metallic mercury vapor < 15.0 µg/m 3 for 24 h 29 Workplace: Organic mercury < 10.0 µg/m 3 1, 30 Metallic mercury vapor < 50.0 µg/m 3 1, 29, 35 Air; Adverse Effects Possible Skin > 30.0 µg/m 3 1 Emissions from individual industrial sites > 2300.0–3200.0 g mercury daily 1 French municipal waste incinerator > 0.3 µg/m 3 for > 24 h 54 Chloralkali Plants, Canada Wastewater effluents < 2.5 g mercury daily per ton of chlorine produced 36 Air emissions < 2.0 µg/m 3 daily 36 Drinking Water Brazil < 0.2 µg/L 2 Turkey < 1.0 µg/L 27 International < 1.0 µg/L 1 United States, most states < 2.0 µg/L 1, 45 Bottled water < 2.0 µg/L 1 Effluent Limitations from Wastewater Treatment Plants Delaware, Oklahoma, Texas < 5.0 µg/L 1 Illinois, Wisconsin < 0.5 µg/L 1 New Jersey < 2.0 µg/L 1 Tennessee < 50.0 µg/L 1 Diet Australia: General diet < 10.0 to < 100.0 µg/kg fresh weight (FW) ration 3 General diet < 20.0 µg/kg FW 43 Seafood < 500.0 µg/kg FW 43 Benelux countries < 30.0 µg/kg FW ration 3 Brazil < 50.0 µg/kg FW ration 3 Canada < 500.0 µg/kg FW ration 4 Malaysia; vegetables; fruit; vegetable and fruit juices; tomato pulp, paste, and puree; tea; coffee, cocoa < 50.0 µg/kg “as consumed” 42 Thailand: General foods < 20.0 µg/kg FW 43 Seafoods < 500.0 µg/kg FW 43 United States < 1000.0 µg/kg FW ration 4, 5 © 2006 by Taylor & Francis Group, LLC PROPOSED MERCURY CRITERIA 279 Table 12.2 (continued) Proposed Mercury Criteria for the Protection of Human Health Variables Criterion or Effective Mercury Concentration Ref. a Japan: Total mercury intake: Adverse effects expected > 250.0 µg daily 34 Nontoxic < 25.0 µg daily; < 0.5 µg/kg BW daily 34 Symptoms of mercury poisoning Consumption of > 500.0 g fish muscle daily containing 10.0 mg methylmercury chloride/kg FW muscle 34 Methylmercury < 600.0 µg/kg BW daily c 34 Permissible Tolerable Weekly Intake Total mercury < 5.0 µg/kg BW 1 Total mercury Maximum of 4.28 µg/kg BW 6 Methylmercury < 3.3 µg/kg BW 1,7 Methylmercury < 170.0 µg 34, 37 Methylmercury; Japan; estimated weekly intake 42.0–52.0 µg 37 Methylmercury < 200.0 µg/60–kg person 34 Fish consumption advisory; Florida vs. most states > 0.5 mg total Hg/kg FW edible aquatic product vs. > 1.0 mg total Hg/kg FW edible aquatic product 8 Fish and Seafood, Edible Parts United States < 300.0 µg total Hg/kg FW 9, 23 United States < 300.0 µg methylmercury/kg FW 46 United States; Food and Drug Administration action level > 1.0 mg Hg/kg FW 47 Florida: Safe < 500.0 µg/kg FW d 38 Limited consumption > 500.0 µg/kg FW and < 1500.0 µg/kg FW e 38 No consumption advised > 1500.0 µg/kg FW 38, 49 Japan: Total mercury < 400.0 µg/kg FW 33, 34, 37 Methylmercury < 300.0 µg/kg FW 33, 34, 37 Slovak Republic < 500.0 µg/kg FW 48 Acceptable intake: 60-kg adult 25.0 µg daily 10 70-kg adult 200.0 µg weekly 10 Adult 500.0 µg weekly 11 Pregnant Women, Diet All < 250.0 µg/kg FW 10 Japan < 400.0 µg/kg FW 3, 32 Canada, Germany, United States, Brazil < 500.0 µg/kg FW 1, 3, 12, 13, Italy < 700.0 µg/kg FW 6 Finland, Israel, Sweden < 1000.0 µg/kg FW 3, 11, 14 Florida; Consumption of Contaminated Fish Containing 2–3 mg Methylmercury/kg FW Muscle Nonpregnant adults Less than 454.0 g fish muscle weekly 24 Women of child-bearing age and children less than 15 years of age Less than 454.0 g fish muscle monthly 24 Shark Flesh Containing 0.5–1.5 mg Hg/kg FW Consumption limited to once weekly by healthy nonpregnant adults 25 Containing more than 1.5 mg Hg/kg FW Consumption prohibited 25 (continued) [...]... non-human mammals, recommended mercury levels include daily intake of < 250.0 µg total mercury/ kg FW body weight, diets that contain < 1.1 mg total mercury/ kg FW, and < 0.002 µg total mercury in drinking water supply of livestock; however, diets of fisheating mammals should contain < 100.0 µg total mercury/ kg FW Tissue mercury concentrations in sensitive mammals (in mg total mercury/ kg FW) should probably... restricted to < 0.6 to 1.1 µg total mercury/ kg body weight Proposed tolerable mercury concentrations include < 0.2 mg/kg FW in blood, < 0.7 mg/kg whole body, and < 6.0 to 50.0 mg/kg in hair; however, adverse neurobehavioral effects have been associated with cord blood concentrations > 5.8 µg methylmercury/L and > 1.0 mg methylmercury/kg DW hair © 2006 by Taylor & Francis Group, LLC 284 MERCURY HAZARDS TO LIVING. .. Kumamoto 867, Japan Scheuhammer, A.M 1988 Chronic dietary toxicity of methylmercury in the zebra finch, Poephila guttata, Bull Environ Contam Toxicol., 40, 123 –130 © 2006 by Taylor & Francis Group, LLC 288 MERCURY HAZARDS TO LIVING ORGANISMS Scheuhammer, A.M., C.M Atchison, A.H.K Wong, and D.C Evers 1998 Mercury exposure in breeding common loons (Gavia immer) in central Ontario, Canada, Environ Toxicol... Kingdom, Sweden — have advised their dentists to specifically curtail installation of mercury- containing amalgam fillings in pregnant women (Anderson et al., 1998) Incidentally, Hujoel et al (2005), in © 2006 by Taylor & Francis Group, LLC 282 MERCURY HAZARDS TO LIVING ORGANISMS a study conducted in Washington state, U.S.), found no evidence that mercury- containing dental fillings placed during pregnancy... acceptable to protect representative species of birds (in mg total mercury/ kg FW) include less than 0.5–< 1.0 in eggs, < 5.0 in feather, < 5.0 in liver, and < 20.0 in kidneys Diets of sensitive fish-eating birds should contain less than 20.0 µg Hg as methylmercury/kg FW or < 100.0 µg total mercury/ kg FW; daily intake should not exceed 640.0 µg total mercury/ kg body weight For most species of non-human mammals,... development of nonmercury technologies to extract gold with minimal environmental damage, measurement of loss rates of mercury through continued periodic monitoring of fishery and wildlife resources in mercury- contaminated areas, and mercury accumulation and detoxification rates in comparatively pristine ecosystems In view of the demonstrable adverse effects of uncontrolled mercury releases into the biosphere... applied at the point of origin to prevent the discharge of potentially harmful mercury wastes Point sources need to be identified and regulated (Facemire et al., 1995) In Sweden, discharges from point sources in the 1950s and 1960s averaged 20 to 30 metric tons annually Since the end of the 1960s, the annual emission of mercury in Sweden has been reduced to about 3.5 tons through better emission control...280 Table 12. 2 (continued) MERCURY HAZARDS TO LIVING ORGANISMS Proposed Mercury Criteria for the Protection of Human Health Criterion or Effective Mercury Concentration Variables Ref.a Foods of Animal Origin < 500.0 µg/kg FW < 50.0 µg/kg FW 15 16 < 500.0 µg/kg FW < 1000.0 µg/kg FW Livestock tissues Wildlife tissues Breast muscle: Domestic poultry... waste incinerators: a health risk assessment with the CalTox multimedia exposure model, Environ Int., 31, 693–701 Grandjean, P., P Weihe, R.F White, F Debes, S Araki, and K Yokoyama 1997 Cognitive deficit in 7-yearold children with prenatal exposure to methylmercury, Neurotoxicol Teratol., 19, 417–428 Gray, J.E (Ed.), 2003 Geologic Studies of Mercury by the U.S Geological Survey USGS Circular 124 8 Available... S Murakami 1989 Mercury pollution in Tokuyama Bay, Hydrobiologia, 176/177, 197–211 National Research Council (NRC) 2000 Toxicological Effects of Methylmercury National Academy Press, Washington, D.C Niimi, A.J and G.P Kissoon 1994 Evaluation of the critical body burden concept based on inorganic and organic mercury toxicity to rainbow trout (Oncorhynchus mykiss), Arch Environ Contam Toxicol., 26, 169–178 . bioconcentration factor of 40,000 for methylmercury and the American oyster, Crassostrea virginica (USEPA, 1985). 276 MERCURY HAZARDS TO LIVING ORGANISMS other aquatic organisms, total mercury. 1.1 mg total mercury/ kg FW; and for livestock, less than 0.002 µg total mercury/ L in the drinking water supply (Table 12. 1). Tissue mercury concentrations in sensitive mammals (in mg total mercury/ kg. LLC 272 MERCURY HAZARDS TO LIVING ORGANISMS Table 12. 1 Proposed Mercury Criteria for the Protection of Selected Natural Resources Resource and Other Variables Criterion or Effective Mercury