Population monitoring using methods of molecular epidemiology combined with reliable data on exposure is an extremely powerful approach to determine the effect of mutagens on human populations. ...Although human blood and urine have traditionally been used for biomonitoring, an increase in the use of placental and buccal smear samples should be expected. As biomarkers of exposure, DNA strand breaks and hemoglobin and albumin adducts seem to be most sensitive. As biomarkers of response, cytogenetic analysis determining chromosome aberrations or micronuclei has been widely used. Additional information can be obtained by using the chromosome painting technique and by determining gene mutations at the hprt locus; however, epidemiological studies exhibiting a relationship between these biomarkers and environmental pollution are still lacking. The use of sperm to analyze the effect of environmental mutagens in germ cells (e.g, sperm morphology and sperm aneuploidy) should be encouraged. The determination of susceptibility by analyzing genetic polymorphism, which is responsible for individual differences in the biotransformation of mutagens and carcinogens, will gain importance for risk assessment. Future research should include validating molecular methods, studying adaptive response to chemical carcinogens, and studying the modulatory effect of antioxidants, as well as the effect of carcinogens on immunity.
The concentrations of four trace metals, namely copper, lead, cadmium and manganese, were determined in six fish species and three crustaceans collected from five sites spanning over 70% of the ...Ghanaian coastline.
Copper and lead were determined in Barracuda (Spraena spraena), the Ribbon fish (Trichiurus lepturus), the Sardine (Sardinella spp), the Sole (Cynoflossus senegalensis), the Sea Bream (Pagrus coupei) and the Soldier fish (Cynapastas marmuratus). Cadmium and manganese were analyzed in the Blue Crab (Callinectes sepidus), the Spiny lobster (Panilirus regius) and the edible shrimp (Crago septempinosus). Sampling sites included Takoradi, Elmina, Cape Coast, Accra and Tema.
Lead and copper in the fishes ranged 0.25-0.94 μgg
−1
fresh weight and 0.40-2.54 μgg
−1
dry weight (FW) respectively whilst cadmium and manganese in the crustaceans ranged 0.05-0.083 μgg
−1
FW and 0.554-1.404 μgg
−1
FW respectively.
The Barracuda accumulated the greatest amount of metals whilst the sardine accumulated the least. with the crustaceans, there was a significant difference between the amounts of the metals accumulated. the blue crab accumulated the greatest and the edible shrimp the least.
The analysis showed that: (i) there was a positive correlation between the metals bioconcentrated and the extent of pollution of the marine waters and (ii) along the Ghanaian Continental Shelf, the extent of pollution was of the increasing order as: Elmina = Cape Coast < Takoradi < Accra < Tema. Pollution of the marine waters could be minimized by control of flow of pollutants from land based activities.
Health effects from environmental toxicants may be a more serious problem in developing countries compared with developed countries because the problem is potentiated by other factors: a) the lack of ...or failure to enforce regulations, which allows human exposures to genotoxic agents; b) undernourishment of the lower economic and social classes that comprise the most exposed populations from industrial and agricultural activities; and c) parasitic infections that afflict a wide range of populations in both urban and rural areas. Data on the genotoxic effects of different types of exposures, including environmental exposures (natural and industrial); occupational exposures, and infections and medical treatments, are presented and discussed with the point of view that all these factors must be taken into account with respect to regulation and the protection of human health. Occupational exposures in developing countries are higher than in developed countries due to lack of stringent regulations, lack of knowledge of the risks involved, and the negligence of workers. General pollution is another important issue since developed countries have established strict regulations and risky industrial processes are being exported to developing countries, along with banned substances and dangerous industrial wastes. It should be emphasized that stringent regulations in developed countries will not prevent exposures in the long term because toxic substances that are released into the environment will ultimately reach all our future generations.
This paper examines the conditions under which it is efficient to transfer liability for contamination of a given piece of property from the seller to the buyer at the time of sale and then, for ...debt-financed sales for which there is a foreclosure, subsequently to the lender who has financed the purchase. We identify two key potential sources of inefficiency, which depend on the relative probabilities that the parties will be judgement-proof at the time liability is imposed. The results suggest that the efficiency effects of liability transfers will depend on the relative magnitudes of these two sources of inefficiency
The Genetic Activity Profile (GAP) database was used to identify and compare agents showing genotoxic activity in humans. The database revealed several substances for which both human and rodent ...cytogenetic data existed. Based on the ratio of the lowest effective doses (LEDs) in rodent versus human studies, humans appear to be at least 10 times more sensitive than rodents to the majority of the genotoxic substances examined. Several caveats are discussed which may be responsible, in part, for the apparent differences in sensitivity. Some of these differences could be due to variations in the test protocols or they may, in fact, reflect real differences between human and rodent cells. However, in contrast to the in vivo comparison, the LEDs for human data from in vitro studies were not uniformly lower than for comparable studies in rodents. The in vitro comparison suggests that the apparent differences in human versus rodent cell sensitivity seen in vivo must be viewed with a degree of caution. Nevertheless, the overall GAPs for these agents, and particularly the human in vivo data, underscore the concern for adequate protection of humans exposed to these environmental mutagens.
Studies were conducted in northern Bohemia to simultaneously evaluate personal exposures to air pollution in the form of respirable particles containing polycyclic aromatic hydrocarbons (PAHs) and ...biomarkers of exposure, biological effective dose, genetic effects, and metabolic susceptibility. The series of biomarkers included PAH metabolites in urine, urine mutagenicity, PAH-DNA adducts in white blood cells determined by32P-postlabeling, PAH-albumin adducts determined by enzyme-linked immunosorbent assay (ELISA), DNA damage in lymphocytes detected by comet assay, chromosomal aberrations, sister chromatid exchanges, and glutathione S-transferase M1 (GSTM1) genotypes. For these studies, a group of women who work outdoors about 30% of their daily time was selected. In a pilot study, a group of women from a polluted area of the Teplice district (northern Bohemia) was compared with a group of women from a control district of southern Bohemia (Prachatice). In a follow-up repeated-measures study, a group of nonsmoking women from Teplice was sampled repeatedly during the winter season of 1993 to 1994. Personal exposure monitoring for respirable particles (<2.5 μm) was conducted for the 24-hr period before collection of blood and urine. Particle extracts were analyzed for carcinogenic PAHs. In the pilot study and in the follow-up study, a highly significant correlation between individual personal exposures to PAHs and DNA adducts was found (r=0.54, p=0.016; r=0.710, p<0.001, respectively). The comet parameter (percentage DNA in tail; %T) correlated with exposures to respirable particles (r=0.304, p=0.015). The GSTM1 genotype had a significant effect on urinary PAH metabolites, urine mutagenicity, and comet parameters (%T and tail moment) when the GSTM1 genotype was considered as a single factor affecting these biomarkers. Multifactor analysis of variance considering exposure and adjusting the data for GSTM1, age, and diet showed that the effect of personal exposurs to PAHs on the variability of biomarkers (DNA adducts, comet parameters, urine mutagenicity) might be higher than the effect of the GSTM1 genotype. These results show the importance of considering all potential factors that may affect the biomarkers being analyzed.
This paper considers how transferring some or all future responsibility for cleanup of a contaminated site affects the current owner's incentives to reduce contamination, given that he anticipates ...selling his property in the future. The results depend on the probabilities that the parties will be judgment-proof, the distribution of surplus, and whether there is joint and several liability. Contrary to popular belief, we show that transferring liability can actually increase the seller's incentive to invest in pollution abatement. Furthermore, abatement incentives are at least as great and generally greater with joint and several liability than without it.
Considering the contemporary debate on themes involving risk situations in contaminated areas, some relevant concepts about risk communication and risk governance are discussed in this article. A ...critical analysis of two case studies on communities exposed to lead Brazil is presented: in Adrianópolis (Ribeira Valley, State of Paraná) and Santo Amaro da Purificação (State of Bahia).
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