W \IH{ 01 HIM ol H< 1 THE IMPACT OF VARIOUS METALS ON THE AQUATIC ENVIRONMENT Rod§rt F. Schneider TECHNICAL REPORT NUMBER 2 _> C O M P L I• -% , -< INVESTIGATIONS - DENVER CENTER DENVER,COLORADO tLEAi FEBRUARY 17, 1971 ------- TABLE OF CONTENTS Page LIST OF TABLES ii SYNOPSIS 1 ARSENIC 1 Water Quality .• 1 Biotic Response ... 2 Standards 2 COPPER 5 Water Quality 5 Biotic Response 5 Standards 6 CADMIUM 6 Water Quality , 6 Biotic Response 9 Standards 9 LEAD 12 Water Quality 12 Biotic Response 12 Standards 12 ZINC 16 Water Quality 16 Biotic Response 17 Standards 17 LITERATURE CITED . 20 ------- LIST OF TABLES No. Page 1 Arsenic (As) Concentration (mg/1) 3 2 Copper (Cu) Concentration (mg/1) 7 3 Cadmium (Cd) Concentration (mg/1) 10 4 Lead (Pb) Concentration (mg/1) 13 5 Zinc (Zn) Concentration (mg/1) 18 ii ------- THE IMPACT OF VARIOUS HEAVY METALS ON THE AQUATIC ENVIRONMENT SYNOPSIS: A literature review of the effects of arsenic, copper, cadmium, lead and zinc species on water quality and aquatic biota is presented. Some synergistic and antagonistic effects are discussed and the existing governmental standards for these metals are summarized. ARSENIC (As) Water Quality Arsenic is a normal constituent of most soils, with concentrations ranging up to 500 mg/kg. In its elemental form, arsenic is insoluble in water, but many of the arsenates are highly soluble. Most, if not all, natural waters contain arsenic compounds. Its natural occurrence is very common in the freshwater of the western United States (McKee and Wolf, 1963). Elsewhere (i.e., New Zealand) lethal doses of arsenic (20 mg/animal Ib.) have been recorded as occurring naturally in freshwater (Grimmett and Mclntosh, 1939). Through domestic water supplies arsenic compounds are constantly taken into the human body where they are cumulative. Human blood normally con- tains 0.2 to 1.0 mg/1 of arsenic (Browning-; 1961). In seawater, normal arsenic concentrations are recorded to be 0.003 mg/1 (Lambou and Lira, 1970a.) As mentioned above, arsenic compounds are cumu- lative in living tissue. Thus, in the sea, marine plants (i.e., brown algae) have been found to contain concentrations up to 30 mg/1 (FWPCA, 1968). Arsenic is also commonly found in marine animals. According to the work of Vinogradov (1953), it accumulates up to 0.3 mg/1 in some molluscs, coelenterates, and crustaceans. McKee and Wolf (1963) report that shellfish may contain over 100 mg/kg. ------- 2 Biotic Response Arsenic is notorious for its toxicity to humans. Ingestion of as little as 100 mg usually results in severe poisoning and as little as 130 mg has proved fatal (Browning, 1961). Several incidents have demonstrated that arsenic in water may be carcinogenic. Cancer of the skin and possibly of the liver is attributed to arsenic in drinking water (Arguello, et. al., 1960; Kathe, J., 1937; Telio, E. E., 1951). Some bioassay work has been done with arsenic, but the results are not based on standard testing methods such as the 96 hour TLm- (see McKee and Wolf, 1963 p. 141 for detailed bioassay results). It is interesting to note that arsenic concentrations of 3-20 mg/1 have not harmed aquatic insects such as immature dragonflies, damselflies, and mayflies (Rudolfs, et. al., 1950). Rudolfs (1944) also reported that concentrations of 2-4 mg/1 of arsenic did not interfere in any way with the self-purification of streams. Standards Most State codes do not specifically cite metals, so the statement made here will probably apply to all the metals discussed herein. Governmental water quality codes often briefly define hazardous metals and for abatement purposes the common code statement is ". . .no toxic materials (metals, often understood) in concentrations that will impair the usefulness of receiving waters as a source of supply or interfere with other legitimate use of said waters". To summarize limits for arsenic in water, as suggested by various agencies, refer to the following table. ------- TABLE 1. Arsenic (As) Concentration (mg/1) Arsenic Concentration 0.05 0.05 0.2 0.2 0.01 0.05 0.05 1.0 1.0 1.0 0.05 1.0 0.05 0.05 0.05 Organization & Date of Recommendation USPHS, 1942 USPHS, 1946 W.H.O., 1958 W.H.O. European, 1961 USPHS, 1962 USPHS, 1962 State of California, 1963 State of California, 1963 State of California, 1963 State of California, 1963 State of Texas, 1967 State of Texas, 1967 State of Colorado (date unknown) State of Florida (date unknown) State of Illinois (date unknown) Comment Maximum permissible concentration in drinking water. Maximum permissible concentration in drinking water. Maximum allowable concentrations for potable water. Tolerance limit for drinking water standards. Recommended limit for drinking water. Maximum allowable limit for drinking water. Maximum limit for domestic water supplies. Maximum limit for irrigation water supplies. Maximum limit for stock and wildlife watering. Maximum limit for fish and other aquatic life waters. Maximum limit for inland waters. Maximum limit for tidal waters. Maximum allowable limit for surface waters to be used for public water supply - after complete treatment. Maximum allowable for surface waters in Florida. Maximum allowable limit for surface waters used for public supply - after complete treat- ment . ------- IABLE 1. Arsenic (As) Concentration (rag/1) - Continued Arsenic Concentration 0.05 0.05 0.01 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Organization & Date of Recommendation State of Indiana (date unknown) State of Iowa (date unknown) State of Minnesota (date unknown) State of Mississippi (date unknown) State of Alaska (date unknown) State of Connecticut (date unknown) State of Maine (date unknown) State of Michigan (date unknown) State of Montana (date unknown) State of Nevada (date unknown) State of Ohio (date unknown) State of Rhode Island (date unknown) State of Vermont (date unknown) Comment Maximum allowable limit for surface waters used for public supply - after, complete treat- ment. Maximum allowable limit for surface waters used for public supply - after complete treat- ment. Maximum allowable limit for surface waters used for public supply - after complete treat- ment. Maximum allowable limit for surface waters used for public supply - after complete treat- ment. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Maximum allowable limit for sur- face waters used for public supply - after complete treat- ment . Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. ------- 5 COPPER (Cu) Water Quality Metallic copper is insoluble in water, but many copper salts are highly soluble as cupric or cuprous ions. Copper (cupric) ions are not likely to be found in natural surface or groundwaters. This is because as they are introduced into natural waters of pH7, or above, these ions quickly precipitate and are thereby removed by adsorption and/or sedimentation (McKee and Wolf, 1963). In natural freshwater, copper salts occur in trace amounts, up to about 0.05 mg/1 (McKee and Wolf, 1963). In seawater, copper is'found at a level of 0.003 mg/1. Therefore, the presence of greater amounts of copper salts is generally the result of pollution, attributable to the corrosive action of the water on copper pipes, to industrial discharges, or frequently to the use of copper compounds for the control of undesirable algae. Copper is not considered to be a cumulative systemic poison, like lead or mercury. In humans, most of the copper ingested is excreted by the body and little is retained. In lower organisms there is some record of accumulation. Marine animals have been found to contain 4 to 50 mg/1 and in some sponges accumulation has exceeded these values (FWPCA, 1968). Biotic Response In concentrations high enough to be dangerous to humans, copper renders a disagreeable taste to the water. Threshold concentrations for taste have been reported in the range of 1.0 - 2.0 mg/1 of copper, while 5.0 - 7.5 mg/1 makes the water completely undrinkable (Schneider, 1931). For this reason it is believed that copper is seldom a hazard to domestic supplies. Copper is present in trace amounts in all living organisms. It is believed to be essential for nutrition. ------- 6 The toxicity of copper to aquatic organisms varies significantly not only with the species, but also with the physical and chemical characteristics of the water (e.g., temperature, hardness, turbidity, and carbon dioxide content). Concentrations, toxic to a variety of aquatic organisms, may vary from 0.015 to 3.0 tng/1 depending upon the water chemistry. Copper acts synergistically with the sulfates of other metals such as zinc and cadmium to produce a potent toxic effect on fish (Anonymous, 1950; Doudoroff, 1952; and Tarzwell, 1958). Synergism also exists between copper and mercury (Corner and Sparrow, 1956). Standards Limits set for copper in water vary markedly. The following table summarizes agency recommendations. CADMIUM (Cd) Water Quality The elemental form of cadmium is insoluble in water, although the chloride, nitrate, and sulfate of this metal are highly soluble. In the literature searched no "normal" level for freshwater was recorded. Mention was made of "normal" levels for seawater of <0.08 mg/1 (FWPCA, 1968). Cadmium salts may be found in wastes from electroplating plants, pigment works, textile printing, lead mines and certain chemical industries. Welsch and Lieber (1954) reported groundwater contamination by cadmium to the ex- tent of 3.2 mg/1 on Long Island, N.Y., as the result of an electroplating industry's waste discharge. High concentrations of cadmium have been re- ported in Missouri mine waters (Anonymous, 1955). One spring in the area had 1,000 mg/1 of cadmium. ------- TABLE 2. Copper (Cu) Concentration (mg/1) Copper Concentration 0.2 3.0 3.0 3.0 0.2 1.0 1.0 1.5 3.0 1.0 1.0 0.1 0.02 0.05 1.0 Organization & Date of Recommendation USPHS, 1925 USPHS, 1942 USPHS, 1946. State of Oklahoma, 1957 State of Oklahoma, 1957 State of Oklahoma, 1957 W.H.O., 1958 W.H.O., 1958 W.H.O. European, 1961 USPHS, 1962 State of California, 1963 State of California, 1963 State of California, 1963 State of California, 1963 State of Texas, 1967 FWPCA, 1968 Comment Mandatory maximum limit for drinking water. Recommended limit for drinking water (not mandatory). Recommended limit for drinking water (not mandatory). Limit for municipal water supply. Limit for agricultural water use. Limit for recreational waters. Permissible limit for drinking water. Excessive limit for drinking water. Limit after 16 hours contact with new pipe, but distribution system should have <0.05 mg/1 copper. Recommended limit for drinking water. Threshold concentration in domestic supplies. Threshold concentration in irrigation supplies. Threshold concentration for freshwater fish and aquatic life. Threshold concentration for seawater fish and aquatic life. Recommended limit for inland and tidal waters. Water Quality Criteria for aquatic life. Maximum copper concentration at any time or place should not be greater than 1/10 the 96-hour ------- TABLE 2. Copper (Cu) Concentration (mg/1) - Continued Copper Concentration 1.0 1.0 0.5 1.0 1.0 1.0 1.0 0.2 Organization & Date of Recommendation FWPCA, 1968 (Continued) State of Alaska (date unknown) State of Connecticut (date unknown) State of Florida (date unknown) State of Illinois (date unknown) State of Maine (date unknown) State of Michigan (date unknown) State of Minnesota (date unknown) State of Minnesota (date unknown) Comment value, nor should any 24-hour average concentration exceed 1/30 of the 96-hour TI^ value. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Maximum allowable limits for surface waters to be used for drinking water, shellfish, fish and wildlife, and industrial water supply. Maximum allowable for drinking water. Maximum allowable for drinking water. Same As USPHS, 1962, Drinking Water Standards. Maximum allowable limit for drinking water. Maximum allowable limit for rec- reation water, fish propagation and wildlife. 1.0 1.0 1.0 1.0 State of Montana (date unknown) State of Nevada (date unknown) State of Rhode Island (date unknown) State of Vermont (date unknown) Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. ------- 9 Biotic Response Cadmium is moderately toxic to all organisms and it is a cumulative poison in mammals. It tends to concentrate in the liver, kidneys, pancreas, and thyroid of humans and other mammals. Common levels found in marine plants are approximately 0.4 mg/1, while in marine animals a range of 0.15 to 3 mg/1 has been recorded (FWPCA, 1968). Few studies have been made of the toxicity of cadmium in the aquatic environment. Medical reports are of little value because the adverse effects of human ingestion vary appreciably from person to person. Aquatic organisms (i.e., Daphnia magna) are currently being exposed to cadmium and other toxic metals via bioassay techniques at EPA's Duluth, Minnesota, laboratories. Preliminary results indicate Daphnia are very sensitive to cadmium; the LC-50 (3 wk.) was 5 mg/1 in Lake Superior water. Other unpublished data (Biesinger, Christensen, Shelhom, in press) reveal no effect to fathead minnows or bluegills exposed to 37 ug/1 through a complete generation. The tests also indicate that following prolonged exposure there is a large accumulation of cadmium in fish (personal com- munication, J. I. Teas ley) . Cadmium acts synergistically with zinc to increase toxicity. Hublou, Wood, and Jeffries (1954) found that cadmium concentrations of 0.03 mg/1 in combination with 0.15 mg/1 of zinc from galvanized screens caused mortality of salmon fry. Standards Because scant data are available as to the long-term adverse effects of cadmium on the environment, the standards are possibly excessively re- strictive. ------- 10 TABLE 3. Cadmium (Cd) Concentrations (mg/1) Cadmium Concentration 0.1 0.0 0.05 0.01 0.02 0.01 0.01 0.01 0.01 0.05 0.01 0.01 Organization & Date of Recommendation USSR, 1949 State of Oklahoma, 1957 W.H.O. European, 1961 USPHS, 1962 State of Texas, 1967 FWPCA State of Alaska (date unknown) State of Colorado (date unknown) State of Connecticut (date unknown) State of Illinois (date unknown) State of Illinois (date unknown) State of Indiana (date unknown) State of Iowa (date unknown) Comment Maximum permissible concentration in domestic supplies of Russia. Suggested criteria for municipal, industrial, agricultural, recre- ation, fish and wildlife water use. Maximum tolerance limit for drinking water. Maximum allowable limit for drinking water. Maximum limit for inland and tidal waters. The concentration of cadmium must not exceed 1/30 of the 96-hour TLjn concentration at any time or place and the maxi- mum 24-hour average concentration should not exceed 1/500 of the 96 -hour TLjn concentration. Same as USPHS, 1962, Drinking Water Standards. Maximum allowable limits for drinking water. Same as USPHS, 1962, Drinking Water Standards. Maximum allowable limit for drinking water. Maximum allowable limit for fish propagation and wildlife waters . Maximum allowable for drinking water. Maximum allowable for drinking water. ------- TABLE 3. Cadmium (Cd) Concentrations (mg/1) - Continued 11 Cadmium Concentration 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Organization & Date of Recommendation State of Maine (date unknown) State of Michigan (date unknown) State of Minnesota (date unknown) State of Mississippi (date unknown) State of Montana (date unknown) State of Nevada (date unknown) State of Ohio (date unknown) State of Rhode Island (date unknown) State of Vermont (date unknown) Comment Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Maximum allowable for drinking water. Maximum allowable for drinking water. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Maximum allowable limit for drinking water. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. ------- 12 LEAD (Pb) Water Quality Some natural waters contain lead in solution, as much as 0.8 mg/1 (Lambou and Lira, 1970b) . These concentrations are most often found in mountain streams flowing through limestone and galena. Surface and ground- waters used for drinking supply in the U.S. often have a trace of lead but it seldom exceeds 0.04 mg/1 (Ohio River Sanitation Commission, 1953). The lead concentration in seawater is about 0.00003 mg/1. It is found in marine plants at a level of 8.4 mg/1. Residues in marine animals reach a concentration in the range of 0.5 mg/1. Lead is highest in calcareous tissue (FWPCA, 1968). Higher concentrations than listed above are usually the result of pollution from mines or leaded gasolines. Biotic Response Lead tends to be deposited in bone as a cumulative poison. Sensitivity to lead poisoning differs with individuals as concentrations causing human sickness may vary from 0.042 to 1.0 mg/1 (Mason, 1908). Abundant bioassay data are available (see McKee and Wolf, 1963 p. 208). Lead has an antagonistic effect with calcium. In soft water, lead may be very toxic at concentrations of 0.1 mg/1 (Doudoroff and Katz, 1953). In hard water these concentrations are not toxic. As a matter of fact, the Ohio River Valley Water Sanitation Commission (Anon., 1950) reported that calcium in a concentration of 50 mg/1 completely destroyed the toxic effect of 1.0 mg/1 of lead. Standards In recent years the USPHS standard for lead in drinking water has been lowered. The major reason for this lowering of limits is that ------- 13 TABLE 4. Lead (Pb) Concentration (mg/1) Lead Concentration 0.1 0.3 0.1 0.1 0.02 0.3 1.0 0.1 0.1 0.1 0.05 0.1 0.1 0.5 Organization & Date of Recommendation USPHS, 1925 Germany, 1933 USPHS, 1942' USPHS, 1946 Uruguay, 1951 Netherlands, 1953 Mersey and Severn River Boards in England (date unknown) W.H.O. International, 1958 International Water Supply Assoc. (USA, Great Britain, France, and Netherlands), 1958 W.H.O. European, 1961 USPHS, 1962 State of California, 1963 State of Texas, 1967 State of Texas, 1967 Comment Maximum permissible concentration in drinking water. Temporary concentration in drinking water that had been in pipes for 24 hours. Maximum permissible concentration in drinking water. Maximum permissible concentration in drinking water. Maximum recommended limit in potable water. Temporary concentration in drinking water that had been in pipes for 24 hours. Working standards for all heavy metals in certain English streams. Maximum allowable limits for lead in drinking water. Maximum allowable limits for lead in drinking water. Maximum tolerance limit for drinking water. Maximum allowable limit for drinking water. Maximum limit for surface waters used by fish or to be processed for human consumption. Maximum limit for inland waters. Maximum limit for tidal waters. ------- TABLE 4. Lead (Pb) Concentration (mg/1) - Continued 14 Lead Concentration 0.05 2-4 8-10 0.05 0.05 0.05 0.05 0.05 0.1 0.05 0.05 0.05 0.05 Organization & Date of Recommendation FWQA, 1970 FWQA, 1970 FWQA, 1970 FWQA, 1970 State of Alaska (date unknown) State of Colorado (date unknown) State of Connecticut (date unknown) State of Florida (date unknown) State of Illinois (date unknown) State of Illinois (date unknown) State of Indiana (date unknown) State of Iowa (date unknown) State of Maine (date unknown) State of Minnesota (date unknown) Comment Physiologically safe in water for lifetime. Physiologically safe in water for period of a few weeks (borderline health hazard thereafter). Toxic in water with exposure of several weeks. Lethal, unknown concentration, probably more than 15 mg/1 for a period of several weeks. Same as USPHS, 1962, Drinking Water Standards. Maximum allowable limit for drinking water. Same as USPHS, 1962, Drinking Water Standards. Maximum allowable limit for drinking water, industrial supply, agriculture, fish propagation and wildlife, and recreation. Maximum allowable limit for drinking water. Maximum allowable limit for fish propagation and wildlife waters. Maximum allowable limit for drinking water. Maximum allowable limit for drinking water. Same as USPHS, 1962, Drinking Water Standards. Maximum allowable limit for drinking water. ------- IA.BLE 4. Lead (Pb) Concentration (mg/1) - Continued 15 Lead Organization & Date Concentration of Recommendation Comment 0.05 State of Mississippi Maximum allowable limit for (date unknown) drinking water. 0.05 State of Nevada Same as USPHS, 1962, Drinking (date unknown) Water Standards. 0.05 State of Ohio Maximum allowable limit for (date unknown) drinking water. 0.05 State of Rh6de Island Same as USPHS, 1962, Drinking (date unknown) Water Standards. 0.05 State of Vermont Same as USPHS, 1962, Drinking (date unknown) Water Standards. ------- 16 control causes little undue hardship on water purveyors, and total cumulative ingestion by the consumer is reduced. ZINC (Zn) Water Quality Some zinc salts (e.g., zinc chloride and zinc sulfate) are highly soluble in water. These salts are often found in industrial wastewater from galvanizing industries, ;and manufacturers of paint pigments, cosmetics, pharmaceutics, dyes, insecticides, and numerous other products. In zinc- mining areas, this metal has been found in natural waters in concentrations as high as 50 mg/1 (American Water Works Assoc., 1950). In most freshwater (surface and ground), zinc is present only in trace amounts. Jacobs (1953) presented some evidence that zinc ions are absorbed strongly and permanently on silt, with the resultant inactivation of the metal. In seawater, the normal zinc concentration is about 0.01 mg/1. Marine plants may contain up to 150 mg/1 of zinc, while marine animals contain ranges of 6 to 1,500 mg/1. High concentrations of zinc in domestic water are undesirable from an aesthetic standpoint as well as from a health hazard standpoint. (Note: health hazards are discussed later.) At a concentration of 30 mg/1, zinc gives water a milky appearance (Kehoe, Cholak, Largent, 1944). Concentra- tions as low as 5.0 mg/1 cause a greasy film on boiling of the water (Howard, 1923). The soluble salts of zinc impart an unpleasant, astringent taste to water and can be detected as low as 4.3 mg/1 (Cohen, Kamphake, Harris, and Woodward, 1960). ------- 17 Biotic Response Zinc has no known adverse physiological effects upon man except at very high concentrations (i.e., 675-2,280 mg/1 causes vomiting). In fact, zinc is an essential and beneficial element in human nutrition (Rothstein, 1953) . Normal uptake by humans is 10-15 mg/day (Browning, 1961). Zinc exhibits its greatest toxicity toward fish and aquatic organisms. In soft water, concentrations of zinc ranging from 0.1 to 1.0 mg/1 have been reported to be lethal, but calcium is antagonistic toward such toxicity. Fish sensitivity to zinc varies with species, age and condition of the fish, as well as the physical and chemical characteristics of the water. Bioassay results are listed in detail by McKee and Wolf, 1963, p. 295). There is some controversy as to a synergistic effect between zinc and copper. Doudoroff and Katz (1953) believe a synergistic effect exists while the Water Pollution Research Board of England (1960) disagrees. The key to this disagreement appears to be the hardness of the water, but more study will be required before a definite statement can be made. Standards Zinc "taste tests" have been partly instrumental in changing the standards for potable supply. This is one reason for the range in limits listed in Table 5. ------- 18 5. Zinc (Zn) Concentration (mg/1) Zinc Organization & Date Concentration of Recommendation 5.0 15.0 15.0 1.0 5.0 15.0 5.0 5.0 5.0 5.0 5.0 1.0 5.0 1.0 USPHS, 1925 USPHS, 1942 USPHS, 1946 Mersey and Severn River Boards in England, 1953 W.H.O. International, 1958 W.H.O. International, 1958 W.H.O. European, 1961 USPHS, 1962 State of Texas, 1967 State of Alaska (date unknown) State of Connecticut (date unknown) State of Florida (date unknown) State of Illinois (date unknown) State of Illinois (date unknown) Comment Maximum permissible concentration in drinking water. Recommended limited concentration in drinking water. Recommended limited concentration in drinking water. Working standards in English streams for all heavy metals in combination with zinc. Permissible limit in drinking water. Excessive limit in drinking water. Recommended limit for drinking water. Recommended limit for drinking water. Maximum limit for inland and tidal waters. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Maximum allowable for drinking water, industrial supply, agri- culture, fish and wildlife, and recreation. Maximum allowable for drinking water. Maximum allowable for fish and wildlife waters. ------- T&BLE 5. Zinc (Z-Q Concentration (mg/1) - Continued 19 Zinc Organization & Date Concentration of Recommendation Comment 5.0 5.0 5.0 5.0 5.0 5.0 5.0 State of Maine (date unknown) State of Michigan (date unknown) State of Minnesota (date unknown) State of Montana (date unknown) State of Nevada (date unknown) State of Rhode Island (date unknown) State of Vermont (date unknown) Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Maximum allowable in drinking water. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. Same as USPHS, 1962, Drinking Water Standards. ------- 20 LITERATURE CITED American Water Works Assoc., 1950. "Water Quality and Treatment", 2nd ed., AWWA. Anon., 1950 "Ohio River Valley Water Sanitation Commission, subcommittee on Toxicities Metal Finishing Industries Action Committee", Report No. 3. Anon., 1955. Ohio River Valley Water Sanitation Commission, "Cadmium", Incomplete Interim Report, Kettering Lab., Univ. of Cincinnati. Arguello, R. A., E. E. Tello, B. A. Macola, and L. Manzano, 1960. "Cutaneous Cancer in Chronic Endemic Regional Arsenicism in the Province of Cordoba, Argentine Republic", Rev. Fac. Ciec. Med. Univ. Cordoba 8, 409 (1950); Proc. Conf. on Physiological Aspects of Water Quality, Public Health Service. Biesinger, Christensen, and Shelhom, 1971, unpublished data. Browning, E., 1961. "Toxicity of Industrial Metals", Butterworths, London, England. Cohen, J. M., L. J. Kamphake, E. K. Harris, and R. L. Woodward, 1960. "Taste Threshold Concentrations of Metals in Drinking Water", Journal AWWA 52, 660. Corner, E. D. S. and B. W. Sparrow, 1956. "The Modes of Action of Toxic Agents. I. Observations on the Poisoning of Certain Crustaceans by Copper and Mercuty", Jour. Mar. Biol. Assoc. V. K. 35,531 Doudoroff, P., 1952. "Some Recent Developments in the Study of Toxic Industrial Wastes", Proc. 4th Annual Pacific N.W. Ind. Waste Conf., State College (Pullman, Washington) 21. Dourdoroff, P. and M. Katz, 1953. "Critical Review of Literature on the Toxicity of Industrial Wastes and Their Components to Fish. II. The Metals, as Salts", Sewage and Industrial Wastes 25, 802. Federal Water Pollution Control Administration, 1968. "Water Quality Criteria", Report of National Technical Advisory Committee, Dept. of Interior, Washington, D.C. Grimmett, R. E. R. and I. G. Mclntosh, 1939. "Occurrence of Arsenic in Soils and Waters in the Waiotapu Valley and Its Relation to Stock Health", N.Z. Jour. Sci. Tech. 21, 138 A (1939); Water Pollution Abs. 13 (July 1940) . Howard, C. D., 1923. "Zinc Contamination in Drinking Water", Jour. AWWA 10., 411. ------- 21 Hublou, W. F., J W. Wood and E. R. Jeffries, 1954. "The Toxicity of Zinc or Cadmium for Chinook Salmon", Oregon Fish Comm., Briefs 5, 1. Jacobs, H L , 1953. "Rayon Waste Recovery and Treatment", Sewage and Ind. Wastes 25, 296. Kathe, J., 1937. "Das Arsen Vordommen bei Reichenstein und die Sogenannte Reichensteiner Krankheit". 110 Jahresbericht der Schlesischen Gesellschaft fuer vaterlaendische Kultr. Medizinisch - naturwissenshaft- liche Reihe, No. 3 Breslau Ferdinand Wirt. Kehoe, R. A., J. Cholak and E: J. Largent, 1944. "The Hygienic Signifi- cance of the Contamination of Water with Certain Mineral Constituents", Jour. AWWA 36, 645. Lambou, V. and B. Lira, 1970a. "Hazards of Arsenic in the Environment, With Particular Reference to the Aquatic Environment"', FWQA, U.S. Dept. of Interior, August 1970 (mimeo.) Lambou, V. and B. Lira, 1970b. "Hazards of Lead in the Environment, With Particular Reference to the Aquatic Environment," FWQA, U.S. Dept. of Interior, August 1970 (mimeo.) Lieber, M. and W. F. Welsch, 1954. "Contamination of Ground Water by Cadmium", Jour. AWWA 46, 541. Mason, W. P., 1908. "Examination of Water (Chemical and Bacteriological)", John Wiley and Sons. McKee, J. E. and H. W. Wolf, 1963. "Water Quality Criteria", 2nd ed. State Water Quality Control Board of California. Publication No. 3-A. Ohio River Water Sanitation Commission, 1953. "Report on the Recommended Physiologically Safe Limits for Continued Human Consumption of Lead in Water", O.R.W.S.C. The Kettering Lab, Coll. Med., Univ. Gin., Cincinnati, Ohio. Rothstein, A., 1953. "Toxicology of the Minor Metals", Univ. Rochester, AEG Proj. UR-262, June 5, 1953. Rudolfs, W., et.al_., 1944. "Critical Review of the Literature of 1943", Sewage Works Jour. 16, 222. Rudolfs, W., G. E Barnes, G. P. Edwards, H. Heukelekian, E. Hurwitz, C. E. Renn, S. Steinberg, and W. F. Vaughan, 1950. "Review of Literature on Toxic Materials Affecting Sewage Treatment Processes, Streams and BOD Determinations", Sewage and Industrial Wastes 22, 1157. Russell, F. C., 1944. "Minerals in Pasture, Deficiencies and Excesses in Relation to Animal Health", Imperial Bur. of Animal Nutrition, Aberdeen, Scotland, Tech. communication 15. ------- 22 Schneider, W. G., 1931. "Copper and Health", Jour. N.E.W.W.A. 44, 485 (1930); Water Pollution Abs. 4 (Sept. 1931). Tarzwell, C. M., 1958. "Disposal of Toxic Wastes", Ind. Wastes 3;2, 48. Tello, E. E. "Hidroarsenicismo Cronico Regional Endemico (Hacre)", Imprinta de la Universidad Cordoba, Rep. Argentina P. 162. Vinogradov, A. P., 1953. "The Elementary Chemical Composition of Marine Organisms", Sears Foundation, New Haven, Connecticut. Water Pollution Research Board of England, 1960. "Report of the Water Pollution Research Laboratory for the Year 1959", Dept. Sci. and Ind. Res., H. M. Stationery Office, London. GPO 838-817 ------- |