摘要:

People make subjective judgments about the severity of environmental problems and on future land use relying on certain information, and on their experiences with the problem. This article examines perceptions of the severity of environmental problems, willingness to expend future funds to solve these problems, and future land use for the Department of Energy's Savannah River Site (SRS) in South Carolina as a function of race. The null hypothesis that there are no racial differences in perceptions was tested. Of those interviewed, 23% of the 399 people were black, 75% were white, and 2% identified themselves as other. Blacks were significantly more willing than whites to spend federal funds to solve environmental problems such as cleaning up the SRS and Superfund sites, fixing ozone depletion, and reducing the threats from radon and hightension power lines. There were statistically significant racial differences in preferences for future land use at the SRS, with blacks having a higher preference for using it as a preserve, and whites having a higher preference for a research park, camping, hiking, and hunting. These results indicate that the environmental concerns of the blacks interviewed were equal to or stronger than those of the whites. This is in contrast to much of previously published work that shows that blacks exhibit lower concerns and actions than whites for environmental problems.

ISSN:1528-7394    

DOI:10.1080/009841098159268

出版商:Informa UK Ltd    

年代:1998

数据来源: Taylor

摘要:

The results of environmental (11 subjects) and biological (57 subjects) monitoring of exposure to mancozeb, ethylenethiourea (ETU), and dim ethoate are reported for employees of a firm producing commercial formulations containing these active ingredients. Urinary excretion \[GM(GSD) ] of ETU (mug/g creatinine) and alkylphosphates \[dimethylphosphate (DMP) + dimethylthiophosphate (DMTP) + dimethyldithiophosphate (DMDTP)] (nmol/g creatinine) was 65.3(4.8) and 419.2(2.1), respectively, for employees engaged in the formulation of a product containing 80% mancozeb (n= 9), 36.6(1.9) and 296.4(2.4) for those formulating a product containing 35% mancozeb (n = 9), 9.5(6.1) and 1022.4(3.0) for those engaged in plant maintenance and internal transport of materials (n = 6), 10.3(4.2) and 322.8(3.3) for those engaged in packaging the mancozeb formulations (n = 16), 4.4(3.3) and 2545.4(3.9) for those formulating a product containing 40% dimethoate (n = 11), and 3.0(2.7) and 871.7(3.3) for those bottling the same dimethoate formulation (n = 10). Air concentrations (mug/m3) ranged from 25.3 to 194.4 for dimethoate, from 0.2 to 1.3 for ETU, and from 139.9 to 949.0 for mancozeb. Urinary excretion of ETU and alkylphosphates showed a significant correlation with mancozeb (r2= .971), and ETU (r2= .858), and dimethoate (r2= .955) contamination of the hands. Potential dose estimates showed that the potential respiratory doses of mancozeb and dimethoate accounted, on the average, for 38% of the total potential dose. The potential respiratory dose of ETU was 7% of the total potential dose. Total estimated absorption did not exceed the accepted daily dose (ADI) for ETU and mancozeb, but the ADI for dimethoate was exceeded. Serum and erythrocyte cholinesterase activities in workers formulating dimethoate products were not significantly different before and after exposure.

ISSN:1528-7394    

DOI:10.1080/009841098159277

出版商:Informa UK Ltd    

年代:1998

数据来源: Taylor

摘要:

The protein binding of atrazine in plasma and its effect on salivary excretion of atrazine was determined in male Sprague-Dawley rats. The degree of protein binding of atrazine was determined at 3 steady-state plasma concentrations, 50, 150, and 250 mug/L, using an ultrafiltration technique. In total, 48 arterial blood samples were collected from 18 rats; 38 of 48 blood samples had their time-matched whole saliva samples. The average protein binding of atrazine ranged from 18% to 37% ; however, it was not significantly different across the 3 steady-state plasma concentrations nor among the individual rats. Overall, 26% of atrazine was bound to plasma proteins and not available for transport from blood into saliva. Protein binding of atrazine in plasma was not correlated with total atrazine plasma concentration nor with free atrazine plasma concentration, which indicates that the protein-bound fraction of atrazine is independent of plasma concentration within the range measured in this study (30-400 mug/ L). The average saliva/ plasma (S/P) concentration ratio of atrazine increased from 0.7 using total atrazine plasma concentration to 0.94 (S/fP) when free atrazine plasma concentrations calculated as 26% of protein binding was used. Salivary concentration was highly correlated with free atrazine plasma concentration. The results suggest that salivary concentration of atrazine not only reflects its total plasma level but accurately measures the portion of atrazine (free atrazine) in plasma, which may be of toxicological significance.

ISSN:1528-7394    

DOI:10.1080/009841098159286

出版商:Informa UK Ltd    

年代:1998

数据来源: Taylor

摘要:

Chlorinated naphthalenes (CNs) and chlorinated biphenyls (CBs), hexachlorobenzene (HCB), and p,p '-DDE were determined in human adipose and liver tissues collected at autopsy of 5 men and 2 women (Swedish), 47-80 yr of age. In paired adipose tissue and liver samples, the differences of the distribution of CNs, CBs, HCB, and p,p '-DDE were small, but the concentrations of the compounds (lipid weight basis) varied between the subjects. Generally, the profiles of the contaminants were similar in the subjects. However, in one of the male subjects (80 yr of age) the concentrations of 1,2,3,5,7/1,2,4,6,7-pentaCN and 1,2,3,4,6,7/1,2,3,5,6,7-hexaCN were much higher in the liver: 6 and 20 times higher than in adipose tissue, respectively. The concentration of the toxic coplanar 3,3',4,4',5-pentaCB (CB-126) was also high in the liver from this individual, three times higher concentration than in adipose tissue. It is suggested that the multiplicity of contaminants found in humans should be taken into consideration in risk assessment and that further studies are needed on the distribution of contaminants in different tissues.

ISSN:1528-7394    

DOI:10.1080/009841098159295

出版商:Informa UK Ltd    

年代:1998

数据来源: Taylor

摘要:

Di- ortho polychlorinated biphenyls (PCBs) are prominent environmental contaminants and their biological activity in fish may be more significant than previously thought. Four weeks after intraperitoneal (ip) injection with 50 or 250 mug 2,2',4,4',5,5'-hexachlorobiphenyl (2HxCB)/ g fish, rainbow trout livers were removed and frozen at-80 C or microsomes were prepared. Microsomal ethoxyresorufin O -deethylase (EROD) activity was approximately one and two orders of magnitude greater than controls in fish treated with 50 and 250 mug 2HxCB/g fish, respectively. Cytochrome P4501A (CYP1A) Western immunoblot relative optical density increased with 2HxCB dose. Hepatic CYP1A1 mRNA levels were approximately threefold greater in fish treated with 250 mug 2HxCB/g fish than in controls, while hepatic CYP1A1 mRNA levels in fish treated with 50 mug 2HxCB/g fish were not significantly induced. There was no increase of CYP1A3 mRNA in 2HxCB-treated fish. The study showed 2HxCB induced hepatic EROD activity, CYP1A protein, and CYP1A1 mRNA content in rainbow trout.

ISSN:1528-7394    

DOI:10.1080/009841098159303

出版商:Informa UK Ltd    

年代:1998

数据来源: Taylor

摘要:

The reproductive, endocrine, and growth effects of developmental lead exposure were assessed using a rat model in which 0.6% lead acetate (w/v) was administered in the drinking water ad libitum during different developmental periods to determine if lead actions were a result of direct effects of continuous exposure to the metal ion or secondary to disrupted neonatal "endocrine imprinting." Sprague Dawley rats were exposed to lead: (1) from gestational d 5 through birth; (2) during pregnancy and lactation; (3) during lactation only; (4) from birth through adulthood; or (5) from gestational d 5 through adulthood. Lead effects were measured on the development of aspects of the reproductive system, adult sex steroid levels, and growth rates in both male and female animals. The relative weights of male secondary sex organs in adult offspring were not significantly affected in any of the lead-treated groups. In contrast, female pups exposed to lead from birth through adulthood or from gestational day 5 through adulthood were observed to have significantly delayed vaginal opening and disrupted estrus cycling. These effects on female reproductive physiology were not observed in animals where lead exposure was confined only to pregnancy or lactation. Significant suppression of adult mean serum testosterone levels was only observed in male pups exposed to lead continuously from gestational age 5 d throughout life. Lead decreased birth weight in all animals exposed in utero and mean body weights were significantly decreased in all lead-treated groups up to weaning. Analysis of growth curves revealed that all lead-treated groups had significantly reduced growth rates during lactation. However, in addition, in male pups exposed to lead during pregnancy and lactation, from birth or from gestational age 5 d, growth rates were also significantly reduced during puberty. Postpubertal growth rates were unaffected in any lead-treated group. Thus, delayed female reproductive development and suppression of adult male serum testosterone concentration required continuous exposure to the heavy metal. Little evidence was observed for an alteration of "endocrine imprinting" by lead on either reproductive or growth parameters. Exposure during early development (pregnancy and lactation) resulted in no permanent effects in this model other than small (10%) decreases in the body weight of pups postpuberty.

ISSN:1528-7394    

DOI:10.1080/009841098159312

出版商:Informa UK Ltd    

年代:1998

数据来源: Taylor