Carcinogenicity study in rats with a mixture of eleven volatile halogenated hydrocarbon drinking water contaminants.

A lifetime carcinogenicity study was carried out in Wistar rats, with a mixture of the following halogenated hydrocarbons: trichloromethane, tetrachloromethane, monobromodichloromethane, trichloroethylene, tetrachloroethylene, 1,2-dichlorobenzene, 1,3,-dichlorobenzene, 1,4,-dichlorobenzene, 1,2,3,-trichlorobenzene, 1,2,4,-trichlorobenzene, 1,3,5-trichlorobenzene. From this mixture 0.22, 2.2, or 22 mg was added per liter drinking water representing concentrations being three orders of magnitude higher than found in several water wells. Most of the changes found in body weight, hematology and pathology correlated with intercurrent diseases or were in accordance with background pathology. With respect to incidence and time of occurrence of tumors, no significant differences were found between the control and the high dose group when lifespan correction was applied. Thus it is concluded that in the present study no significant toxic or carcinogenic effects are induced by lifetime exposure of rats to a mixture of volatile halogenated hydrocarbons in the drinking water.

Toxicity, biodegradability, and accumulation of a number of Cl/N-containing compounds for classification and establishing water quality criteria.

The evaluation of the ecotoxicity of chemical compounds is often hampered by the scarcity of the literature data on toxicity, biodegradability, and accumulation. In this study additional data on 16 Cl/N-containing organic compounds were gathered by laboratory experiments. For assignment to so-called gray or black lists, two different classification schemes were used. According to both schemes 3-nitrotoluene, 1,2- and 1,3-dichlorobenzene, the 1-chloro-nitrobenzenes, 2,3-dichloronitrobenzene, 2-chloroaniline, and 2-chloro-4-nitroaniline were marked as black list substances, primarily based on poor biodegradability; 2- and 4-nitrotoluene, nitrobenzene, and 2-methoxyaniline were classified as gray list substances. For 3- and 4-methoxyaniline and 1,4-dichlorobenzene no agreement in classification was obtained. Additionally, water quality criteria are proposed for 2-, 3-, and 4-nitrotoluene and nitrobenzene, based on long-term toxicity data: respectively 0.3, 0.2, 0.4, and 1.0 mg/liter.

Bromide-ion balance of a polder district with large-scale use of methyl bromide for soil fumigation.

When concentrations of bromide ion were determined in waters in a polder district of The Netherlands where there is large-scale use of methyl bromide for soil fumigation, the maximum concentrations in precipitation, surface water and ground water were found to be 0.98, 41 and 17 g/m3, respectively. The highest concentrations of bromide ion in surface water were found in September-October during the main fumigation season. For the period 1 September 1979 to 31 August 1980 a bromide-ion balance was computed for the polder district. The contribution of the use of methyl bromide to the input of bromide ion in the polder district was 215 Mg (Mg = 1000 kg), which corresponds to 68% of the total input of bromide ion (318 Mg). On average over a year, about 14% of the dosage of methyl bromide applied for soil fumigation was converted to bromide ion.

Non-occupational exposure to pentachlorophenol: clinical findings and plasma-PCP-concentrations in three families.

1 The clinical findings are reported of 15 members of three families living in houses where relatively large amounts of pentachlorophenol (PCP) solutions had been applied. To be able to interpret the plasma concentrations in the patients, plasma-PCP-concentrations in 99 draftees were measured. The clinical and toxicological-analytical results are discussed. 2 Signs of a systemic PCP-intoxication were not found in any patient. 3 Symptoms and objective changes of the uncovered skin were present in three patients (a burning painful sensation, erythema, dryness and scaling) possibly caused by a direct influence of PCP in the air. 4 The plasma-PCP-concentrations in the patients ranged from 25-660 micrograms 1(-1). The mean plasma-PCP-concentrations in the draftees was 128.6 +/- 134.9 micrograms 1(-1) (mean +/- s.d.); the median was 88 micrograms 1(-1), the 95% range was 330 micrograms 1(-1). 5 There was an association between patients' plasma-PCP-concentrations and their staying in the affected house.

Organochlorines, cholinesterase inhibitors, and aromatic amines in Dutch water samples, September 1969--December 1975.

The Dutch aquatic environment was monitored from September 1969 to December 1975 for organochlorine pesticides and their metabolites, cholinesterase inhibitors, and aromatic amines. The 1,492 samples analyzed included surface water, rainwater, groundwater, and drinking water. The highest concentrations of hexachlorobenzene (HCB) and alpha- and beta-benzene hexachloride (BHC) were found in the Rhine River and its tributaries. Concentrations of the compounds in the Dutch part of the Rhine River decreased downstream. Other organochlorine pesticides and their metabolites, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin alpha- and beta-endosulfan, and sigmaDDT were detected occasionally, but only in low concentrations. Cholinesterase inhibitors and aromatic amines were always present in the Rhine River and its tributaries.