Long-term carcinogenicity study in Syrian golden hamster of particulate emissions from coal- and oil-fired power plants.

Male Syrian golden hamsters were given 15 weekly intratracheal instillations with suspensions of coal fly ash or oil fly ash. Controls were instilled with saline containing gelatine (0.5 g/100 mL) or to check particle effects with suspensions of hematite (Fe2O3). The common weekly dose was 4.5 mg/hamster. In addition, one subgroup of hamsters was treated with oil fly ash at a weekly dose of 3.0 mg/hamster and another with coal fly ash at a weekly dose of 6.0 mg/hamster. Other groups of hamsters were treated with suspensions of benzo[a]pyrene (BaP) or with suspensions on coal fly ash, oil fly ash, or Fe2O3 coated with BaP. The mass median aerodynamic diameters of the coal and oil fly ashes were 4.4 microns and 28 microns, respectively. Hamsters treated with oil fly ash showed a higher frequency of bronchiolar-alveolar hyperplasia than hamsters in the other treatment groups. Squamous dysplasia and squamous metaplasia were most frequent in animals treated with suspensions of BaP or BaP-coated particles. The earliest appearance of a tumor, the highest incidence of tumors, and the highest incidence of malignant tumors were observed in hamsters treated with oil fly ash coated with BaP. Squamous cell carcinoma and adenosquamous carcinoma were the most frequent malignant tumors. No malignant tumors and only few benign tumors were observed in hamsters instilled with suspensions of fly ash not coated with BaP. The present study gives no indication that coal fly ash could create more serious health problems than oil fly ash.

Use of the microscreen phage-induction assay to assess the genotoxicity of 14 hazardous industrial wastes.

The Microscreen phage-induction assay, which quantitatively measures the induction of prophage lambda in Escherichia coli WP2s(lambda), was used to test 14 crude (unfractionated) hazardous industrial waste samples for genotoxic activity in the presence and absence of metabolic activation. Eleven of the 14 wastes induced prophage, and induction was observed at concentrations as low as 0.4 pg per ml. Comparisons between the ability of these waste samples to induce prophage and their mutagenicity in the Salmonella reverse mutation assay indicate that the phage-induction assay detected genotoxic activity in all but one of the wastes that were mutagenic in Salmonella. Moreover, the Microscreen assay detected as genotoxic five additional wastes that were not detected in the Salmonella assay. The applicability of the Microscreen phage-induction assay for screening hazardous wastes for genotoxic activity is discussed, as are some of the problems associated with screening highly toxic wastes containing toxic volatile compounds.

Acute toxicity of vegetable oil factory effluent to some freshwater teleosts in relation to size.

Specimens of Cirrhina mrigala (Ham.), Labeo rohita (Ham.) and Channa punctatus (Bl.) falling in the size (total length) range of 5.5 +/- 1.0 cm to 27.0 +/- 2.0 cm were exposed to different concentrations of the vegetable oil factory effluent for evaluating the influence of size on the acute toxicity of the factory effluent. The results suggest that relative toxicity of the effluent decreased with increase in the size of the fish. However, for specimens exceeding 20.0 +/- 1.6 cm in size, the toxicity of the effluent increased with an increase in size of the fish. The results also indicate that C. mrigala was most susceptible, while C. punctatus was least susceptible to the effluent.

The in vitro effects of selected environmental toxicants on two heme synthesis enzymes.

Benzene and some of its substitution products become environmental toxicants due to improper disposal procedures. Benzene has been found to alter heme and globin synthesis in anucleate rabbit reticulocytes (Forte et al., 1976; Wildman et al., 1976) and based on these findings we felt it would be useful to determine what, if any, effect these derivatives would have on heme synthesis in vitro by studying their influence on delta-aminolevulinic acid synthetase (ALAS) and ferrochelatase (FC) activities in rat liver homogenates. ALAS was measured according to Ebert et al. (1970). FC was measured after Williams et al. (1980). Final concentrations of each added compound to the reaction mixture were 10(-3) to 10(-6) M. Normal values for rat liver ALAS were 250-350 nmol ALA/g protein/30 min, mean 290 +/- 40, and for FC were 12-40 mumol heme/g protein/45 min, mean 20 +/- 7. At 10(-3) M and lower concentrations these compounds inhibited ALAS and stimulated FC activities. Their effect on ALAS activity expressed as percentage of control of three analyses performed in triplicate +/- SEM was: o- and p-dinitrobenzenes-46 +/- 2; trinitrotoluenes-55 +/- 2; dinitrotoluenes-70 +/- 2; and amino-dinitrotoluenes-171 +/- 4. The stimulatory effect of these compounds expressed as percentage of control +/- SEM on FC was: dinitrotoluenes-171 +/- 3; dinitrobenzenes-152 +/- 3; trinitrotoluenes-142 +/- 4; and amino-dinitrotoluenes-130 +/- 4. Other classes of compounds tested did not significantly affect these enzymes at the same concentrations. These in vitro techniques may prove useful for predicting in vivo toxicologic effects of pollutants on species of interest.

Genetic toxicology in industry: perspectives and initiatives.

Recent studies support the view that, incidents apart, synthetic chemicals in general present only an industrial hygiene problem. It is also apparent that, if performed well, the Salmonella assay plus a genetically independent eukaryotic assay will be sufficient to detect genotoxins in vitro, while the in vivo micronucleus assay, linked to a liver genotoxicity assay, will alert to significant carcinogens. Some 'carcinogens' are not genotoxic, are weak and are usually species/organ specific in their action; they should be recognized as different and treated separately. Cancer bioassays could probably be discontinued except in special cases. Current protocols for such assays often yield misleading data and are unnecessarily expensive. When seeking significant environmental carcinogens and mutagens it would be profitable to turn away from industrial chemicals, despite the fact that they are readily available. In summary, it is suggested that there now exist short-term methods from the results of which it is possible to decide, with a high level of certainty, whether a compound will be a rodent carcinogen at dose levels that may be relevant to man.

Genetic toxicology in industrial practice: general introduction.

During the past decade, important position statements on mutagenicity testing have been issued by industrial organizations such as CEFIC (the European Council of Chemical Industry Federations) and ECETOC (the European Chemical Industry Ecology and Toxicology Centre). Mutagenicity testing is of potential value as a research tool for screening new compounds, as a probe for the identification of harmful substances and as a diagnostic tool for monitoring the health of individuals exposed to certain chemicals. The problems inherent in mutagenicity testing include specificity and sensitivity, and meaningful interpretation of test data will depend on the strict maintenance of accepted quality standards.

The role of mutagenicity testing in the ecotoxicological evaluation of industrial discharges into the aquatic environment.

An important task of ecotoxicology is to provide data for use by governments as a scientific basis for regulating the discharge of potentially hazardous substances into the environment. The criteria on which such regulations are based include biological and chemical degradability, bioavailability (accumulation) and toxicity, the latter manifesting itself in a reduced ability of organisms to survive and reproduce. There are also arguments for including the mutagenicity of chemicals in these criteria. In the past decade many studies have revealed the contamination of water and the atmosphere by mutagens originating in human activities and having observable effects on organisms in these environments. The extent to which this mutagenic stress can alter ecosystems as a whole is not yet known, but if mutagens are shown to cause major changes, mutagenicity is clearly an important ecotoxicological criterion. In the meantime its use must be based on the actual damage caused to organisms by mutagens and on the rising concern over a novel ecological phenomenon that might be named 'increased mutagenic stress'. A detailed report on the ecotoxicological case history of the discharge from a nitrofuran factory demonstrates the role of mutagenicity tests in the evaluation of effluents. As well as being toxic to algae, the discharge was found to be mutagenic in the Ames test. Toxicity and mutagenicity were used as criteria in studies of the biodegradability of the offending substances in a chemostat, as well as in studies to monitor the success of detoxification attempts. In the chemostat the mutagens did not appear to be very degradable but the algal toxicity decreased by 90%. Detoxification was reasonably successful for the mutagens in contrast to the algal toxicants.

Long-term exposure to sulfur dioxide, sulfuric acid mist, fly ash, and their mixtures. Results of Studies in Monkeys and guinea pigs.

Groups of cynomolgus monkeys and guinea pigs were exposed to mixtures of sulfur dioxide, fly ash, and sulfuric acid mist. The exposure concentrations varied between 0.1 and 5.0 ppm for sulfur dioxide, 0.1 and 1 mg/cu m for sulfuric acid mist, while a concentration of approximately 0.5 mg/cu m was used for fly ash. The duration of exposure was 52 weeks for guinea-pigs and 78 weeks for monkeys. Pulmonary function tests and serum biochemical and hematological analyses were conducted prior to and periodically during the exposure period. At the termination of exposure, the lungs were examined microscopically. Analysis of the data revealed that in groups exposed to the mixtures of pollutants, sulfuric acid mist was responsible for the effects observed. No synergistic action between the pollutants was detected.

Issues on health risk assessment at hazardous waste sites and resource recovery facilities in Region II.

This paper examines the issues involved in health risk assessments at hazardous waste sites and resource recovery facilities in Region II and emphasizes the programmatic aspects of the problem and the integration of risk assessment into the permitting process for these facilities. Suggestions for the R&D agenda and policy needs to support a risk assessment strategy in this area are also discussed.

Toxicity of an in situ oil shale process water to rainbow trout and fathead minnows.

An in situ oil shale process water, designated Omega-9 water, was used in flow-through bioassays with fathead minnows, rainbow trout and rainbow trout eggs. Of the two fish species, rainbow trout were more sensitive to acute exposure to Omega-9 water with 96-hour LC50 dilutions of 0.51% and 0.41% in two independent determinations. In embryo-larval studies, the length of fry from eggs hatched and maintained in 0.16% process water was significantly less than that of eggs hatched in control water. A solution of the 13 major inorganic constituents of Omega-9 water, with a 96-hour LC50 of 0.56% for rainbow trout, showed that inorganics accounted for most of the acute toxicity of Omega-9 water.

Identification of cocarcinogens and promoters in industrial discharges into and in the Illinois River.

Organic compounds were isolated from grab or composite samples of industrial and municipal discharges and of the Illinois River by liquid-liquid extraction or adsorption on activated carbon or XAD-2 resin columns. Of the 213 different compounds identified and semiquantitated by gas chromatography-mass spectrometry in 16 samples, 74 were long-chain hydrocarbons or their derivatives. Although their toxicological significance in the environment at the levels found is unknown, the widespread presence of these cocarcinogens and promoters (often found in conjunction with known initiators) may make them significant environmental toxicants. Some evidence for this is the fact that serial dilutions of the extracts were highly toxic to Salmonella typhimurium in the Ames assay, while weak mutagenicity was occasionally detected.

Effects of petroleum refinery wastewater exposure on gill ATPase and selected blood parameters in the Pacific staghorn sculpin (leptocottus armatus).

1. The effects of in vivo exposure to various concentrations of petroleum refinery wastewater on gill ATPase, plasma protein, plasma osmolarity, and hematocrit were measured in the euryhaline fish, Leptocottus armatus. 2. The extent of the reduction in Na,K-ATPase activity resulting from the exposure to the two refineries wastewaters may be related to wastewater chemical composition. 3. Changes in the blood chemistry parameters did not follow a consistent or easily explainable pattern.

Physiological responses of rainbow trout in a pulp and paper mill recipient during four seasons.

The toxicity of pulp and paper mill effluents was estimated by exposing rainbow trout to the effluents in situ during four seasons. The experiments were carried out using one control group and three test groups at different distances from the discharge. After a 10-day exposure mainly hematological parameters were determined from the caged fish. The caging site affected most of the 15 parameters analyzed (blood Hct, MCHC, erythrocyte, and leucocyte counts; plasma gluc, prot, urea, Ca2+, Mg2+). Some changes were detected even at the farthest caging site, 8 km from the discharge. The time of year strongly influenced the results. Seasonal variation exceeded the variation caused by caging site. In addition, the season influenced the responses of rainbow trout to the effluent in many parameters. None of the responses detected were observed in all the experiments. The only significant changes in the median values of the parameters from the caging experiments were a decrease in the plasma Mg2+ and an increase in the plasma K+ concentration.

Mutagenicity of coal fly ash: a new bioassay for mutagenic potential in a particle feeding ciliate.

The use of the established mutagenesis assay in Paramecium as a prescreen for hazardous environmental particles is described. Since these protozoans ingest particles of the size respired by animals and man, the biological effects of the respirable fraction of fly ash particles were monitored in particle-feeding eukaryotic cells. Fly ash from coal combustion was utilized for these studies and was found to be mutagenic. The effects of physical and chemical treatment of the particle mutagenicity provided evidence for both heat-stable, heat-labile and acid extractable mutagenic agents.

Acclimatization of roach, Rutilus rutilus (L.), to toxic components of kraft pulp mill effluents.

Roach (Rutilus rutilus) were exposed, along with their appropriate controls, to a simulated bleached kraft mill effluent (KME-Sa + CP) first for 38 days at a concentration of 0.035 X LC50 and then for 14 days at 0.07 X LC50. During the experiment, their tolerances to KME-Sa + CP were tested five times by measuring the 48-hr LC50 values. In addition, the growth of roach was monitored. At the end of the exposure, accumulation of [14C]pentachlorophenol in various parts of the fish (total PCP in water 15.6 micrograms/liter) was measured. When the fish were preexposed to KME-Sa + CP, the acute tolerance of this mixture in roach increased by 30-39%, but the response was abolished in 31 days. Fish growth remained unchanged during the experiment. Measurement of PCP accumulation revealed no difference in the absorption rate, but under steady-state conditions the degree of bioconcentration was 16% lower (P less than 0.02) in preexposed roach than in their unexposed controls. This difference was entirely accounted for in the head and visceral parts of the fish. Even when no final changes were noted in tolerance and growth rate of the fish, the authors suggest that the significantly lowered body burden implied acclimatizatory compensation under subchronic exposure of this xenobiotic.

Evaluating promulgated refinery effluent standards using artificial streams.

Two-week tests on an Artificial Refinery MIxture (ARM) were conducted on periphyton communities on glass slides in laboratory streams. ARM components, which are present in "typical" refinery effluents, approximate maximum allowable concentrations as promulgated by the 1977 U.S. Environmental Protection Agency (USEPA) guidelines for refinery effluents. ARM concentrations tested ranged from approximately 0.25 to 5 times full strength. The nontaxonomic structural parameters--ash-free dry weight, chlorophyll a, and ATP--indicated that ARM concentrations of 1 to 5X stimulated periphyton colonization rates. ARM concentrations of 0.25 to 5X caused a shift in dominant periphytic algae from diatoms in reference streams to green algae in dosed streams; this resulted in higher pH levels in reference streams, apparently related to photosynthetic activity. Changes in nontaxonomic structural parameters of slides precolonized with periphyton were not sensitive water quality indicators. Dry weight was not a useful biomass indicator due to high levels of suspended solids in ARM. The promulgated 1977 guidelines may be adequate to maintain nontaxonomic structural integrity of periphyton communities, while the 1983 guidelines appear to be adequate to maintain taxonomic integrity.

Cytotoxic and mutagenic properties of shale oil byproducts. I. Activation of retort process waters with near ultraviolet light.

Cultured Chinese hamster ovary (CHO) cells were exposed to dilutions of shale oil retort process waters obtained from three different retorting processes located in the Green River oil shale formations in the western part of the United States. Although the intensity of the response was dictated by thd process water used, all induced a cytotoxic (reduction in colony-forming ability) and mutagenic (induced at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus) response in cells pretreated with dilutions of the waters and subsequent exposure to near ultraviolet light (NUV). Combinations of process water plus NUV yielded mutation frequencies as great as 50% that witnessed for the mutation frequency induced by the potent carcinogen far ultraviolet light. NUV alone was nontoxic and nonmutagenic at the doses of radiation used. Exposure of CHO cells in the dark to nontoxic dilutions of the process waters resulted in small but significant increases in 6-thioguanine resistant mutants. (1-2 time background rates). The biological consequences resulting from the disposal of retort process waters into the delicate environment present in this oil shale region could be further complicated by this photoactivating process.

Port Pirie Cohort Study: environmental exposure to lead and children's abilities at the age of four years.

We studied the effect of environmental exposure to lead on children's abilities at the age of four years in a cohort of 537 children born during 1979 to 1982 to women living in a community situated near a lead smelter. Samples for measuring blood lead levels were obtained from the mothers antenatally, at delivery from the mothers and umbilical cords, and at the ages of 6, 15, and 24 months and then annually from the children. Concurrently, the mothers were interviewed about personal, family, medical, and environmental factors. Maternal intelligence, the home environment, and the children's mental development (as evaluated with use of the McCarthy Scales of Children's Abilities) were formally assessed. The mean blood lead concentration varied from 0.44 mumol per liter in midpregnancy to a peak of 1.03 mumol per liter at the age of two years. The blood lead concentration at each age, particularly at two and three years, and the integrated postnatal average concentration were inversely related to development at the age of four. Multivariate analysis incorporating many factors in the children's lives indicated that the subjects with an average postnatal blood lead concentration of 1.50 mumol per liter had a general cognitive score 7.2 points lower (95 percent confidence interval, 0.3 to 13.2; mean score, 107.1) than those with an average concentration of 0.50 mumol per liter. Similar deficits occurred in the perceptual-performance and memory scores. Within the range of exposure studied, no threshold dose for an effect of lead was evident. We conclude that postnatal blood lead concentration is inversely related to cognitive development in children, although one must be circumspect in making causal inferences from studies of this relation, because of the difficulties in defining and controlling confounding effects.

Use of limited protocols to evaluate the genotoxicity of hazardous wastes in mammalian cell assays: comparison to Salmonella.

Dichloromethane extracts of four diverse hazardous wastes (coke plant, herbicide manufacturing, pulp and paper, and oil refining) were evaluated for mutagenicity in strains TA98 and TA100 of Salmonella. These extracts also were tested for biological activity in short-term mammalian cell assays, including mutagenicity in L5178Y/TK +/- mouse lymphoma cells, chromosomal aberrations and sister chromatid exchanges in Chinese hamster ovary (CHO) cells, morphological transformation in BALB/c-3T3 cells, and teratogenic potential in mouse limb bud cells. The mammalian cell assays were performed using limited protocols that consisted of a preliminary testing of the extracts for cytotoxicity in CHO cells in order to estimate the appropriate dose range for the other assays. These assays were then performed once with only a few doses of extract; all but the mouse limb bud assay were performed in the presence of metabolic activation. Although all four of the wastes were presumptively positive for either mutation or cytogenetic effects, none of the wastes transformed BALB/c-3T3 cells. Further studies are needed to establish which mammalian cell assays, if any, might be useful complements to the Salmonella assay for the purpose of screening hazardous wastes.