Biomedical subjects

M Gochfeld

Publications and source records attributed to M Gochfeld.

At least 19 recordsLinked to original sources

PubMed1992

Heavy metal and selenium concentrations in black skimmers (Rynchops niger): gender differences.

Most studies of heavy metals and selenium have not examined or have failed to find differences in concentrations in the tissues of birds as a function of size or sex. Heavy metal and selenium concentrations were analyzed in breast feathers of adult black skimmers Rynchops niger, a species with marked sexual size dimorphism in which males average 35% heavier than females. Females had significantly higher concentrations of lead and cadmium than males, but there were no gender differences in mercury, selenium, chromium, manganese, and copper despite the marked sexual dimorphism in body size. There were no significant correlations of bird weight or wing length and metal and selenium concentrations, and few correlations among metal and selenium concentrations in the feathers.

Animals↗

PubMed1992

Heavy metal and selenium levels in young cattle egrets from nesting colonies in the northeastern United States, Puerto Rico, and Egypt.

Colonially-nesting species of herons and egrets breed mainly in coastal areas, along rivers or near other large bodies of water. Such areas are also preferred for human development, exposing nesting birds to various pollutants. From 1989-1991, the concentrations of heavy metals and selenium were studied in the feathers of fledgling cattle egrets Bubulcus ibis, a terrestrially-feeding insectivore, from New York and Delaware in the northeastern United States, from Puerto Rico, and from Egypt. There were geographic differences in the concentrations of lead, mercury, cadmium, manganese, selenium, and chromium in the feathers of these egrets. Lead levels were 41 times higher in the feathers of cattle egrets from Cairo compared to the other sites. This difference was attributed to the continuing use of leaded gasoline and the dense automobile traffic in Cairo. However, other differences remain unexplained. Similarly, levels of chromium and manganese were also higher in Cairo than at any other sites. Cadmium levels were similar at all places except for higher levels in eastern Puerto Rico. Mercury concentrations were twelve times higher in the feathers of cattle egrets at Aswan compared to Cairo. In Puerto Rico, we also compared levels in adult cattle egrets with young and found higher concentrations of mercury and manganese, but lower concentrations of selenium in the adults. Using feathers from young cattle egrets is a potentially sensitive tool for biomonitoring for metals, especially lead, since they reflect the local area surrounding the breeding colony.

Animals↗

PubMed1992

Temporal scales in ecological risk assessment.

The process of human health risk assessment (HRA) was formalized in 1983 by the National Research Council to include hazard identification, dose-response analyses, exposure assessment and risk characterization. Risk assessment for ecologic endpoints is emerging as a new discipline. Although environmental impact statements have been conducted for many years, ecologists, managers and policy makers are beginning to formalize the process in terms of risk, and are adapting the HRA paradigm to ecological risk assessment (ERA). In this paper it is suggested that the temporal scales of the two processes differ, and that these differences should be incorporated in ecological risk assessment. Even when HRA techniques are applied to a single non-human species there are temporal variations including: (1) different and often variable life spans, (2) unpredictable lengths of lifestages and different metamorphic stages, and (3) indeterminate growth in some species. When these differences are considered for multispecies assemblages, the impact on the food web will result in exposures of differing magnitudes affecting different species. The challenges for ERA include developing general principles for estimating or predicting exposure to critical life stages of the dominant species in an ecosystem, and establishing the appropriate temporal scales for predicting impacts or evaluating outcomes.

Ecology↗

PubMed1992

Trace element distribution in growing feathers: additional excretion in feather sheaths.

The use of feathers is a non-invasive and repeatable method for biomonitoring trace element levels in birds and their ecosystems. Trace element levels were examined in different parts of growing flight feathers from young common terns (Sterna hirundo) to determine distribution of heavy metals and selenium, potential bias from using partially grown feathers, and whether additional heavy metals and selenium are excreted in feather sheaths that are sloughed before feathers are usually sampled. Lead and mercury levels were significantly higher in the distal fully formed portion of the growing feather (with no residual blood supply) compared to the proximal, growing portion of the feather with a residual blood supply, but no significant differences were evident for cadmium and selenium. These results suggest that using partially grown feathers underestimates the amount of lead and mercury in fully formed feathers and that higher levels of lead and mercury are sequestered in feathers than are present in the blood at any one time. Significantly higher concentrations of lead and cadmium, and significantly lower levels of mercury were in the sheath compared to the whole feather blade. These data suggest that birds excrete more lead and cadmium during molt than previously thought.

Animals↗

PubMed1992

Comparison of lead levels in bone, feathers, and liver of herring gull chicks (Larus argentatus).

Bone, feathers, and liver were analyzed for lead in herring gull chicks (Larus argentatus) of two different ages. The highest levels were found in the bone, evidence of chronic exposure. No differences were found within the bones. Differences occurred between different bones, with the ribs having twice the amount of lead than any other bone. These studies indicate that type of bone affects lead levels; thus researchers should clearly state which parts of which bones are examined. It is also suggested that for humans consistent location should be used for analysis by in vivo X-ray fluorescence.

Age Factors↗

PubMed1992

Medical surveillance and screening in the workplace: complementary preventive strategies.

The terms medical surveillance and medical screening have sometimes been used interchangeably in the occupational medicine literature. Recently attempts have been made to redefine these as mutually exclusive, by nesting surveillance under screening or vice versa, by subsuming both under medical monitoring or periodic examinations, or by eliminating use of the term medical surveillance altogether. In this paper I argue that medical surveillance and medical screening represent discrete concepts and approaches and should be viewed as distinct and complementary secondary preventive components of an occupational health program. Medical surveillance refers to the periodic examination of putatively exposed workers, and is therefore a longitudinal approach. Medical screening refers to the cross-sectional testing or evaluation of a group of workers. Biological monitoring, whether defined narrowly or broadly, focuses on exposure to particular toxicants and should serve as a component of medical surveillance (or of medical screening), not as an independent complement to environmental monitoring. Medical surveillance must function in the context of a comprehensive occupational health program that includes industrial hygiene and education and does not in itself suffice as a comprehensive occupational health program. It is useful to clarify these terms because some of the ethical issues as well as medical controversies over their utility arise from a misunderstanding of what constitutes medical surveillance and how it should be applied.

Cross-Sectional Studies↗

PubMed1992

Exposure assessment for heavy metal ingestion from a sport fish in Puerto Rico: estimating risk for local fishermen.

Sport or subsistence fishermen sometimes underestimate the risks from eating local fish and distrust authorities regarding potential hazards from fish. We report on lead, cadmium, selenium, and mercury levels in snook, locally called robalo (Centropomus spp.), consumed by local fishermen in Puerto Rico, who ate up to 23 fish/wk. Median levels (in ppb, dry weight) for muscle, adipose, and liver ranged from 683 to 780 for lead, 37 to 600 for cadmium, 50 to 146 for mercury, and 361 to 3986 for selenium. Lead levels were similar in all tissues, and selenium and cadmium levels were highest in the liver. Mercury was higher in muscle than in liver. Computing exposure via ingestion for the average fisherman indicated that if one were to consume robalo throughout the year one would be exposed in excess of the EPA Reference Dose (RfD) for mercury. Using a widely accepted maximum consumption of 200 g/d for fishermen yielded hazard indices (daily consumption/RfD) below 1 for all four metals, with a value approaching 1 for mercury in adults, and over 1 for 16-kg children. The possibility that in certain localities and cultures sport or subsistence fishermen may consume fish at levels substantially above 200 g/d should be investigated in performing risk assessments, particularly outside the continental United States.

Adipose Tissue↗

PubMed1992

Metal levels in regrown feathers: assessment of contamination on the wintering and breeding grounds in the same individuals.

Birds are useful indicators of environmental contamination because they are relatively large, conspicuous, top predators in food chains. However, concentrations of contaminants in a bird's tissues reflect the bird's exposure over wide temporal and spatial scales. Birds are most useful as monitors of exposure when these scales are known. In this paper we report concentrations of lead, cadmium, mercury, and selenium in breast feathers of common terns (Sterna hirundo) and roseate terns (S. dougallii) trapped during incubation at breeding colonies in New York and Massachusetts. Terns arrived on the breeding grounds with breast feathers grown on their wintering grounds, and regrew certain feathers that were plucked for analysis. The regrown feathers were themselves plucked, and both sets of feathers were analyzed. For roseate terns at Cedar Beach and common terns at both sites there was a significant increase in mercury levels in the feathers grown on the breeding grounds compared to those grown on the wintering ground. The differences in mercury were far greater at Bird Island than at Cedar Beach. Selenium levels at Cedar Beach were higher for the regrown feathers than the initial feathers for roseate terns, but not for common terns. Lead and cadmium levels were not significantly different at either site for either species. These results suggest that terns are exposed to significantly higher levels of mercury in the northeastern United States than they are in the wintering grounds in South America.

Animals↗

PubMed1992

Survival and reproduction in Peromyscus leucopus in the laboratory: viable model for aging studies.

White-footed mice Peromyscus leucopus reared in our laboratory from wild-caught parents lived at least to 5.5 years. Once past weaning, over 80% of the mice lived at least until two years. Females maintained a constant weight whereas the weight of males increased until four years and decreased thereafter. At four-years of age both sexes bred successfully with mates of the same age, but had lower success with younger mice. Some males and females reproduced at five years of age.

Aging↗

PubMed1991

Lead, mercury, and cadmium in feathers of tropical terns in Puerto Rico and Australia.

Levels of lead, cadmium, and mercury were examined in breast feathers of terns nesting on offshore islets near Culebra, Puerto Rico and on Michaelmas Cay and Heron Island on the Great Barrier Reef, Australia. Levels of all metals in these tropical terns were predicted to be lower than those of terns nesting in temperate regions, because the tropical species feed offshore of non-industrial areas where contamination should be less than for temperature-nesting species that feed in inshore estuaries near industrialized areas. This prediction was not supported by the evidence. In Puerto Rico, lead and cadmium levels were highest in bridled tern (Sterna anaethetus), and mercury levels were highest in sooty (S. fuscata) and roseate tern (S. dougallii). In Australia, levels of lead and mercury were higher in black noddy (A. minutus) and lower for sooty tern; and cadmium levels were highest for brown noddy (A. stolidus) and sooty tern, and lowest for black noddy. Metal levels for the tropical terns nesting in Puerto Rico and Australia generally were not lower than levels reported for temperate-nesting or mainland nesting birds (except for mercury in Australia).

Animals↗

PubMed1991

Employee assistance program compliance: impact of contrasting insurance coverage.

Employee assistance programs are offered by employers to assist employees with personal problems through professional evaluation of the problem and referral to an appropriate treatment source. Although some research has been conducted to document the effect of these programs on such variables as absenteeism and disciplinary action, little information is available regarding compliance with clinical recommendations, ie, initiating and remaining in prescribed treatment. The present study evaluated the effect of two different rates of insurance coverage for outpatient mental health services offered by two comparable blue-collar organizations. Employees from the organization with a higher rate of payment were significantly more likely to initiate treatment and to remain in treatment longer. This outcome was not accounted for by demographic differences between the groups or by differences in diagnostic categories or treatment approaches. Implications of this finding are discussed as well as the utility of an employee assistance program to prepare employees for treatment.

Adult↗

PubMed1991

Quality assurance audits of medical surveillance programs for hazardous waste workers.

The Occupational Safety and Health Administration (OSHA) Hazardous Waste Operations and Emergency Response Regulation (29 CFR 1910.120) requires medical surveillance examinations for hazardous waste workers. We investigated the consistency and appropriateness of the services provided under OSHA 29 CFR 1910.120 as part of a quality control audit. Our study revealed that in most cases the required paperwork including fitness for duty and restrictions or limitations was completed. However, it is also apparent that many of the components of a complete occupational history were not performed. Spirometric examinations often were performed incorrectly. Documentation of baseline tests was not uniformly done, nor were patients always informed of the findings of their examinations. Our study indicated there may be a lack of education, training, and experience of occupational health providers. This suggests that further efforts should be made to educate physicians and nurses providing medical surveillance and other services to hazardous waste workers.

Adult↗

PubMed1991

Fishing a superfund site: dissonance and risk perception of environmental hazards by fishermen in Puerto Rico.

Risk perception studies show that individuals tend to underestimate significant risks, overestimate negligible ones, and distrust authorities. They also rely on a variety of strategies or heuristics to reach decisions regarding their risk-taking behavior. We report on a survey of fishermen and crabbers engaged in recreational and substance fishing in a Puerto Rican estuary (near Humacao), which has been declared a "Superfund site" because of suspected contamination by mercury, and at ecologically similar control sites. Nearly everyone interviewed at the Humacao site was aware of the mercury contamination, but either denied its importance, believed the contamination was restricted to a distant part of the estuary, or assumed that the estuary would be closed by the authorities if the threat was real. All site-users consumed the fish and crabs they caught. At Humacao, the average catch was 7 fish per fishermen (mostly tilapia, Tilapia mossambica, and tarpon, Megalops atlantica) and 13 crabs per crabber (all blue crabs, Callinectes sapidus). On average, the site-users returned to the lagoons about 3-4 times per month. At control sites, fewer fish were eaten. The worst case consumption of tarpon, a species which concentrated mercury at Eastern Puerto Rico, provided an exposure exceeding the EPA reference dose, whereas consumption of one tarpon per week did not entail excess exposure. Fortunately, few individuals caught tarpon exclusively. Unlike counterparts in the northeastern United States, they trusted authorities and indicated that they would have heeded warnings of mercury contamination posted where they fished.

Animals↗

PubMed1991