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M H Sweeney

Publications and source records attributed to M H Sweeney.

At least 19 recordsLinked to original sources
PubMed2003

Information dissemination and use: critical components in occupational safety and health.

BACKGROUND: Information dissemination is a mandated, but understudied, requirement of occupational and environmental health laws and voluntary initiatives. Research is needed on the factors that enhance and limit the development, transfer, and use of occupational safety and health information (OSH). Contemporary changes in the workforce, workplaces, and the nature of work will require new emphasis on the dissemination of information to foster prevention. METHODS: Legislative and regulatory requirements and voluntary initiatives for dissemination of OSH information were identified and assessed. Literature on information dissemination was reviewed to identify important issues and useful approaches. RESULTS: More than 20 sections of laws and regulations were identified that mandated dissemination of occupational and environmental safety and health information. A four-stage approach for tracking dissemination and considering the flow of information was delineated. Special areas of dissemination were identified: the information needs of the changing workforce, new and young workers; small businesses; and workers with difficulty in understanding or reading English. CONCLUSIONS: We offer a framework for dissemination of OSH information and underscore the need to focus on the extent to which decision-makers and others receive and use such information. More solid data are also needed on current investments in disseminating, diffusing and applying OSH information and on the utility of that information. Am. J. Ind. Med. 44:515-531, 2003. Published 2003 Wiley-Liss, Inc.

Humans↗
PubMed2001

Spontaneous abortion, sex ratio, and paternal occupational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

There is conflicting research regarding an association between fetal death and paternal exposure to Agent Orange, a phenoxy herbicide widely used in Vietnam that was contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Men who worked in the U.S. factories that produced Agent Orange were exposed to TCDD at levels hundreds of times higher than TCDD levels in the general population. Wives of TCDD-exposed chemical workers and wives of nonexposed neighborhood referents were interviewed to determine reproductive history. Paternal serum TCDD level at time of conception was estimated for each pregnancy using serum samples taken in 1987. Estimated TCDD levels of workers during or after exposure were high (median, 254 ppt; range, 3-16,340 ppt) compared to referent levels (median, 6 ppt; range, 2-19 ppt). No association between paternal TCDD level at the time of conception and spontaneous abortion was observed among pregnancies fathered by workers with TCDD levels of < 20 ppt [odds ratio (OR) = 0.77; 95% confidence interval (CI), 0.48-1.22], 20 to < 255 ppt (OR = 0.81; 95% CI, 0.40-1.63), 255 to < 1,120, (OR = 0.69; 95% CI, 0.30-1.58), and >or= 1,120 ppt (OR = 0.95; 95% CI, 0.42-2.17) compared to pregnancies fathered by referents. The sex ratio [males/(males + females)] of offspring also did not differ by TCDD exposure (0.53 and 0.54 among workers and referents, respectively). We did not find an association between paternal serum TCDD level and spontaneous abortion or sex ratio of offspring in this population. The estimated TCDD levels in this exposed worker population were much higher than in other studies, providing additional evidence that paternal TCDD exposure does not increase the risk of spontaneous abortion at levels above those observed in the general population. The study could not evaluate the effect of father's childhood or prenatal TCDD exposure on subsequent sex ratio.

Abortion, Spontaneous↗
PubMed2001

Major changes in human ocular UV protection with age.

PURPOSE: Age-dependent human lens coloration may be explained by the binding of UV filters to crystallins. It has been proposed that glutathione may compete for reaction with UV filter degradation products and therefore protect crystallins from modification. To understand this process, UV filters were quantified together with oxidized and reduced glutathione in human lenses of varying age. METHODS: Lens tissues were homogenized in ethanol to extract the UV filters. Metabolites were quantified by HPLC and correlations between them in the nuclear and cortical regions of the lens were examined. RESULTS: The concentrations of the UV filters 3-hydroxykynurenine, kynurenine, and 3-hydroxykynurenine glucoside decreased linearly with age, with slightly lower levels in the nucleus than the cortex. 4-(2-Amino-3-hydroxyphenyl)-4-oxobutanoic acid glucoside was found in higher levels in the nucleus than the cortex and decreased slowly in both regions with age. Glutathionyl-3-hydroxykynurenine glucoside was present in higher concentrations in the nucleus, barely detectable in young lenses, but increased significantly after age 50. Reduced glutathione levels were lower in the nucleus and decreased in both regions with age, yet oxidized glutathione increased in the nucleus but remained constant in the cortex. CONCLUSIONS: Results are consistent with a predominantly nuclear origin for both 4-(2-amino-3-hydroxyphenyl)-4-oxobutanoic acid glucoside and glutathionyl-3-hydroxykynurenine glucoside. This is in accord with their proposed mechanism of formation, which involves an initial deamination of 3-hydroxykynurenine glucoside. This process is more pronounced in older lenses, possibly because of the barrier to diffusion. The barrier may also explain the increase in nuclear oxidized glutathione that is observed with age.

Adolescent↗
PubMed2000

A retrospective job exposure matrix for estimating exposure to 2,3,7, 8-tetrachlorodibenzo-p-dioxin.

BACKGROUND: A job exposure matrix was developed to estimate the 2,3, 7,8-tetrachlorodibenzo-p-dioxin exposure of 3,538 workers who produced 2,4,5-trichlorophenol and its derivatives. METHODS: Daily TCDD exposure scores that were plant, process, and period specific were estimated for each job title as the product of 1) the concentration of TCDD (microg/g); 2) a qualitative factor to account for the extent of worker contact and 3) time exposed to TCDD contamination. Daily scores were summed to compute individual cumulative TCDD exposure scores. RESULTS: Daily TCDD exposure scores ranged from 0.001 to 1,250. Cumulative TCDD scores ranged from 0.002 to 1,559,430. The 393 workers with records of chloracne in the TCDD exposure cohort (11%) had markedly higher cumulative scores than those with no record of chloracne (a median score of 11,546 vs. 77). CONCLUSIONS: The cumulative TCDD exposure scores incorporate both duration and level of exposure, and permit the relative ranking of worker exposures for the evaluation of exposure-response relationships between TCDD exposure and mortality in an updated cohort study analysis.

Algorithms↗
PubMed2000

Human health effects after exposure to 2,3,7,8-TCDD.

In 1949, the first descriptions of human exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD)-contaminated chemicals were reported after a trichlorophenol reactor explosion in Nitro, West Virginia, USA. Reported non-cancer health effects included a range of conditions affecting most systems. Additional reports of the health consequences of exposure continued through the remainder of the century. The majority of effects have been reported among highly exposed groups including occupational populations, such as chemical production workers, pesticide applicators, and individuals who handled or were exposed to materials treated with 2,3,7,8-TCDD-contaminated pesticides, and among residents of communities contaminated with tainted waste oil (Missouri, USA) and industrial effluent (Seveso, Italy). For only six exposed populations were biological measurements of 2,3,7,8-TCDD-contaminated collected and used to examine the relationship between non-cancer health effects and exposure. Of the many non-cancer health effects thought to be associated with 2,3,7,8-TCDD exposure, only chloracne, elevations in GGT and triglyceride levels, and alterations in FSH and LH were related to serum 2,3,7,8-TCDD levels. Mortality from cardiovascular diseases also appeared to be elevated among cohorts of exposed chemical workers and Seveso residents. Continued surveillance of the health of exposed populations will be useful in identifying the long-term effects of both high and low 2,3,7,8-TCDD exposure.

Accidents↗
PubMed1999

Age-related changes in the kinetics of water transport in normal human lenses.

Magnetic resonance microscopy (MRM) has been used to study the kinetics of water transport in human eye lenses. Fresh lenses obtained from the Queensland Eye Bank were incubated at 34.5 degrees C in artificial aqueous humour (AAH) containing nutrients and metabolites similar to those that are present in vivo. MR images were acquired over approximately a 20 hr period following replacement of H(2)O based AAH with deuterium oxide (D(2)O) based AAH. NMR signal intensity from the lenses decreased with time corresponding to a decrease in concentration of H(2)O within the lenses. A statistically significant correlation (P<0.001) was found between the rate of NMR signal loss from the lens nuclei and increasing age of the lenses. The results show that as lenses age, there is a reduction in the rate at which water and presumably also water soluble low molecular weight metabolites, can enter the cells of the lens nucleus via the epithelium and cortex. A decrease in the rate of transport of water, nutrients and anti-oxidants (e.g. glutathione) would be expected to lead to progressive oxidative damage to lenses with age, and may ultimately contribute to presbyopia and senile nuclear cataract.

Aging↗
PubMed1999

Evaluation of diabetes mellitus, serum glucose, and thyroid function among United States workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

OBJECTIVE: Some studies suggest that exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) may affect glucose metabolism and thyroid function. To further assess the relation between exposure to TCDD and endocrine function, data from the largest morbidity study of industrial workers exposed to TCDD were examined. METHODS: A cross sectional study of workers employed > 15 years earlier in the manufacture of 2,4,5-trichlorophenol or one of its derivatives at two United States chemical plants was conducted. The referent group consisted of people with no occupational exposure to phenoxy herbicides and were recruited from the neighbourhoods where the workers lived. RESULTS: A total of 281 workers and 260 unexposed referents participated. The mean current serum lipid adjusted TCDD concentration among workers was 220 pg/g lipid, and among referents was 7 pg/g lipid (p < 0.05). The half life extrapolated TCDD concentrations (the estimated TCDD concentration when occupational exposure to TCDD stopped) among workers averaged 1900 pg/g lipid (range: not detected--30,000 pg/g lipid). Overall, the prevalence of diabetes mellitus was not significantly different between the workers and referents. Also, there was not a significant positive trend between prevalence of diabetes and increasing serum TCDD concentration. However, diabetes was found in six of 10 (60%) workers with current serum TCDD concentrations > 1500 pg/g lipid. After excluding subjects being treated for diabetes, workers in the group with the highest half life extrapolated TCDD concentrations had a significantly increased adjusted mean serum glucose concentration compared with referents (p = 0.03). Workers were also found to have a significantly higher adjusted mean free thyroxine index compared with referents (p = 0.02), especially among workers in the group with the highest half life extrapolated TCDD concentrations. However, no evidence was found that workers exposed to TCDD were at increased risk of thyroid disease. CONCLUSIONS: These findings provide modest evidence that exposure to TCDD may affect thyroid function and glucose metabolism.

Blood Glucose↗
PubMed1998

An impediment to glutathione diffusion in older normal human lenses: a possible precondition for nuclear cataract.

Human age-related nuclear cataract is associated with progressive and widespread oxidation of proteins, particularly in the centre of the lens. The reasons for the onset of cataract and why this disease should take place only in the lenses of older individuals remain unclear. However, a common feature of nuclear cataract is the low concentration of reduced glutathione (GSH) in the centre of the lens. GSH is the principal lenticular antioxidant of the lens and it is synthesized and regenerated in the lens cortex. In this study we investigated the diffusion of glutathione within the human lens as a function of age. Normal human lenses were incubated in artificial aqueous humor containing [35S]cysteine and the label was metabolically incorporated into GSH. After 48-h incubation, lenses were sectioned and phosphorimaging was used to determine the distribution of 35S label. In young lenses, label appeared to diffuse uniformly throughout the whole lens. By contrast, in lenses over the age of 30, very little 35S had penetrated to the centre of the lens. A distinct zonal pattern of label distribution was noted in the older lenses after 48 h incubation, which had dimensions of approximately 7.2 mm (diameter) by 2.8 mm (axial). In some older lenses this pattern was noticeable even after 96-h incubation. Thus a barrier to the diffusion of GSH was observed in older normal lenses which was not present in younger lenses. Furthermore, the internal zone thus delineated has dimensions that coincide with those of the coloured and sclerotic zone present in nuclear cataract lenses. Since nuclear cataract is a disease of the elderly, and maintenance of GSH is known to be vital for lens clarity, we propose that the development of a barrier to the movement of GSH from its site of synthesis and regeneration in the cortex, into the nucleus in older normal lenses, may over time allow oxidative modification of protein to take place in the nucleus, resulting ultimately in nuclear cataract.

Adolescent↗
PubMed1998

Immunological markers among workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

OBJECTIVES: To examine the association of immune cell number and function with occupational exposure to substances contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). METHODS: A cross sectional medical survey. The exposed participants were employed at two chemical plants between 1951 and 1972 in the manufacture of 2,4,5-trichlorophenate and its derivatives. The reference group consisted of people with no occupational exposure to phenoxy herbicides who lived within the communities of the workers. Data from a total of 259 workers and 243 unexposed referents were included in the analysis of immune function. Laboratory tests for immune status included enumeration of circulating leukocyte and lymphocyte populations, proliferative responses of circulating lymphocytes to mitogens and antigens, and serum concentrations of the major immunoglobulins and complement factor C3. RESULTS: The workers had substantial exposure to substances contaminated with TCDD, as indicated by a lipid adjusted mean serum TCDD concentration of 229 ppt compared with a mean of 6 ppt in the unexposed referents. Workers were divided into categories based on their serum TCDD concentration. For all categories except the lowest, with values of serum TCDD comparable with the unexposed referents, there were increased odds of having lower counts of CD26 cells (activated T cells) (odds ratio (OR) 1.0, 95% confidence interval (95% CI) 0.5 to 1.8 for TCDD < 20 ppt; OR 1.6, 95% CI 0.8 to 3.2 for TCDD 20-51 ppt; OR 2.7, 95% CI 1.4 to 5.1 for TCDD 52-125 ppt; OR 2.6, 95% CI 1.4 to 4.9 for TCDD 125-297 ppt; OR 2.4, 95% CI 1.3 to 4.6 for TCDD 298-3389 ppt). A less consistent finding was decreased spontaneous proliferation of cultured lymphocytes. However, increases were found in proliferation of lymphocytes in response to concanavalin and pokeweed in workers in the high TCDD category. Age, cigarette smoking, and alcohol were significant predictors of several immunological outcomes. CONCLUSIONS: Associations between serum TCDD concentration and both a decrease in circulating CD26 cells and decreased spontaneous background proliferation were the major findings of this study. These results are unlikely to be of clinical importance but may reflect limited evidence for an association between immunological changes in workers and high serum concentrations of TCDD, or chance findings resulting from the evaluation of multiple immunological variables.

Adult↗
PubMed1998

Evaluation of cardiovascular outcomes among U.S. workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

Some animal studies and some human studies suggest that exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) may be associated with adverse effects on the cardiovascular system. As part of a cross-sectional medical study comparing workers employed 15 years earlier in the manufacture of 2,4,5-trichlorophenol or one of its derivatives at two U.S. chemical plants with an unexposed comparison group, we examined the association between TCDD exposure and various cardiovascular outcomes. A total of 281 workers and 260 unexposed referents participated. The workers had substantial exposure to TCDD, as demonstrated by significantly elevated mean serum TCDD concentration of 220 pg/g of lipid, compared with 7 pg/g of lipid among the referents. No significant association was found between TCDD exposure and any of the cardiovascular outcomes including myocardial infarction, angina, cardiac arrhythmias, hypertension, and abnormal peripheral arterial flow. Although our study had sufficient statistical power to detect an elevated risk for cardiac arrhythmias, hypertension, and abnormal peripheral arterial flow, it had low power (approximately 50%) to detect an elevated risk for myocardial infarction and angina. Our review of the literature suggests that our negative findings are consistent with those from other cross-sectional medical studies. Although several mortality studies of TCDD-exposed cohorts found significantly increased risks for cardiovascular disease mortality, similar increased risks were not observed in other mortality studies. The data available do not provide definitive conclusions but indicate that further examination of the association between TCDD exposure and cardiovascular disease should be pursued.

Aged↗
PubMed1997

Proportionate mortality among unionized construction ironworkers.

This report presents the results of proportionate mortality ratios (PMR) and proportionate cancer mortality ratios (PCMR) among 13,301 members of the International Union of Bridge, Structural, and Ornamental Ironworkers who had been members for a minimum of 1 year, were actively paying dues into the death beneficiary fund, and had died between 1984-1991. Using the United States proportionate mortality rates as the comparison population, statistically significant elevated risks, using 95% confidence intervals (CI), were observed for several types of injuries: falls (N = 259, PMR = 3.57, CI = 3.15-4.03), transportation injuries (N = 363, PMR = 1.22, CI = 1.10-1.35), and other types of injuries (N = 225, PMR = 1.63, CI = 1.43-1.86). The deaths due to falls were significantly elevated for each 10-year age group under age 60 (PMR > 7.00) and for those workers with < 20 years in the union (PMR > 6.00). Elevated mortality risks were also observed for all malignant neoplasms combined (N = 3,682, PMR = 1.09, CI = 1.06-1.13) as well as for site-specific malignant neoplasms of the lung (N = 1,523, PMR = 1.28, CI = 1.21-1.35), pleural mesothelioma (N = 7, PMR = 1.67, CI = 0.67-3.44) and "other and unspecified sites" (N = 307, PMR = 1.29, CI = 1.15-1.44). The category "pneumoconiosis and other respiratory diseases" was also significantly elevated (N = 690, PMR = 1.11, CI = 1.03-1.20); in this category, deaths due to asbestosis had the greatest elevated risk (N = 10, PMR = 3.56, CI = 1.70-6.54). No elevation in risk was found for kidney cancer or for chronic nephritis which were of interest because of Ironworkers' potential exposure to lead. The present study underscores the importance of fall protection and other injury prevention efforts in the construction industry, as well as the need to control airborne exposures to asbestos, welding fumes and other respirable disease hazards.

Accidents, Occupational↗
PubMed1996

Tradeswomen's perspectives on occupational health and safety: a qualitative investigation.

Qualitative research methods were used to determine the health and safety concerns of women employed in the construction trades. Major categories of concern were identified, including: 1) exposure to chemical and physical agents; 2) injuries from lifting/bending/ twisting, falling, and lacerations; 3) lack of proper education and training; and 4) the health and safety risks related specifically to tradeswomen. Many of the issues identified by the workers are amenable to change through either engineering, behavioral, or administrative interventions.

Accidents, Occupational↗
PubMed1995

Proportionate mortality among construction laborers.

This report presents the results of proportionate mortality ratio (PMR) analyses and proportionate cancer mortality ratio (PCMR) analyses among the 11,685 members of the Laborers' International Union of North America (LIUNA), who died between 1985-1988, using U.S. proportionate mortality rates as the comparison population. Statistically significant elevated mortality risks were observed for all malignant neoplasms (N = 3285, PMR = 1.13, CI = 1.09-1.17), as well as for site-specific neoplasms of the lung (N = 1208, PCMR = 1.06, CI = 1.00-1.12), stomach (N = 170, PCMR = 1.44, CI = 1.23-1.68), and thyroid gland (N = 10, PCMR = 2.24, CI = 1.07-4.12). The PCMRs for these malignant neoplasms were elevated among both white and non-white males, regardless of length of union membership, in most 10-year categories of age at death above 40 and for the three largest LIUNA regions examined. The study also observed 20 mesothelioma deaths, which indicated that some LIUNA members had been previously exposed to asbestos. Statistically significant elevated risks were also observed for deaths from transportation injuries (N = 448, PMR = 1.37, CI = 1.25-1.51), falls (N = 85, PMR = 1.34, CI = 1.07-1.66), and other types of injuries (N = 245, PMR = 1.61, CI = 1.42-1.83). The deaths due to injuries were most often observed among those members who had the shortest amount of time within the union, were younger, and first entered the union after 1955. This is the first study that has examined the general mortality experience limited to construction laborers only (Bureau of Census code 869).

Accidents, Occupational↗
PubMed1995

Induction of P-450 in workers exposed to dioxin.

OBJECTIVES: To examine the effects of occupational exposure to substances contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on cytochrome P-4501A2 activity in a cross sectional medical survey. METHODS: The exposed workers had been employed at two chemical plants > 15 years earlier in the manufacture of 2,4, 5-trichlorophenol and its derivatives. The control group consisted of people with no occupational exposure to phenoxy herbicides and who lived within the communities of the exposed workers. A total of 58 workers and 125 unexposed controls participated in the analysis. Cytochrome P-450 activity was assessed with test that measures caffeine metabolites in the urine. A ratio of metabolites of caffeine (CMR) constituted a measure of P-4501A2 activity. RESULTS: Compared with the control group in multivariate logistic regression, raised non-significant associations were found for three of four categories of TCDD in exposed workers (TCDD < 20 pg/g, odds ratio (OR) 1.7, 95% confidence interval (95% CI) 0.6 to 5.0, TCDD 20-66, OR 0.3, 95% CI 0.0 to 1.7; TCDD 67-147, OR 2.3, 95% CI 0.6 to 8.8; TCDD > or = 148, OR 3.1, 95% CI 0.8 to 12.5). We found a strongly significant association of CMR and urinary cotinine, a measure of smoking, and urinary free ethanol. We found weak non-significant associations between P-4501A2 activity and increased serum TCDD among workers. CONCLUSIONS: The absence of an association between serum TCDD and cytochrome P-4501A2 may be due to the size of the study, insensitivity of the CMR to assess cytochrome P-4501A2 activity, or inadequate levels of exposure, although these were among the highest in human groups tested.

Adult↗
PubMed1995

Ethical considerations, confidentiality issues, rights of human subjects, and uses of monitoring data in research and regulation.

Biomarkers are potentially powerful tools for use in research and regulation. Their derivation from biologic specimens collected from human subjects does, however, present many ethical implications. Ethical issues are relevant in almost each facet of human biomarker research studies: design, identification and recruitment of subjects, handling and use of the data, and interpretation and communication of results. Researchers also face a number of dilemmas when considering the use of human biologic specimens and new biomarkers. The mere fact that such markers are the result of measurements in human specimens gives the appearance of being more accurate than traditional sources of information such as questionnaires or environmental monitoring; yet, this may not always be the case. The meaning of the results of biomarker studies may be unclear because the purpose of the study is usually for research rather than clinical purposes. There generally are no established normal ranges for biomarkers and the interpretation of findings are often difficult. Researchers may not communicate these results to subjects or consider followup action because the task may be too difficult or undefined, or the reaction of the subject cannot be anticipated. A wide range of practices in this regard exists among researchers. Many questions remain unanswered about the use of biologic specimens. These include questions of ownership and access to specimens. Related to this is the question of whether specimens collected for one research purpose can be used for an entirely different research purpose. This is still an open question.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Specimen Banks↗
PubMed1994

Total serum testosterone and gonadotropins in workers exposed to dioxin.

Human reproductive endocrine data may be an important source of epidemiologic information in regard to the toxic potential of 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin). The association of serum dioxin with total serum testosterone, luteinizing hormone, and follicle-stimulating hormone was examined in 248 chemical production workers from New Jersey and Missouri plants and 231 nonexposed neighborhood referents who participated in a medical evaluation in 1987. In linear regression analyses, current serum dioxin was positively and significantly related to luteinizing hormone and follicle-stimulating hormone and inversely related to total testosterone after adjustment for potential confounders (p < 0.05). These trends were also apparent in logistic regression analyses, in which the authors examined the odds ratios of high luteinizing hormone (> 28 IU/liter), high follicle-stimulating hormone (> 31 IU/liter), and low testosterone (< 10.4 nmol/liter) by serum dioxin quartiles. There was a greater prevalence of high luteinizing hormone among workers in the second (odds ratio (OR) = 1.9, 95% confidence interval (CI) 0.7-5.5), third (OR = 2.5, 95% CI 0.9-7.3), and fourth (OR = 1.9, 95% CI 0.7-5.0) quartiles of serum dioxin compared with referents. For follicle-stimulating hormone, the authors observed a greater prevalence of high follicle-stimulating hormone among workers in the fourth quartile (OR = 2.0, 95% CI 0.7-5.6) compared with referents. Similarly, the prevalence of low testosterone was two to four times greater among workers in the second (OR = 3.9, 95% CI 1.3-11.3), third (OR = 2.7, 95% CI 0.9-8.2), and fourth quartiles (OR = 2.1, 95% CI 0.8-5.8) than among referents. The trends observed in these data offer human evidence of alterations in male reproductive hormone levels associated with dioxin exposure. The results support the animal literature in which dioxin-related effects have been observed on the hypothalamic-pituitary-Leydig-cell axis and on testosterone synthesis.

Adult↗