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Biomedical subjects

V Foa

Publications and source records attributed to V Foa.

At least 19 recordsLinked to original sources
PubMed1997

Minimal immunological effects on workers with prolonged low exposure to inorganic mercury.

OBJECTIVES: This study was carried out to investigate possible immunological changes in workers with prolonged low exposure to inorganic mercury in a fluorescent light bulb factory. METHODS: 29 immunological variables were examined in 34 workers with prolonged low level exposure to inorganic mercury (exposed workers) and 35 unexposed workers as the controls. The selected indicator of mercury exposure was concentration of mercury in the urine (U-Hg), which declined progressively from 36.0 micrograms/l in 1978 to 6.0 micrograms/l in the study year 1994. RESULTS: None of the exposed workers had ever shown signs of either acute or chronic inorganic mercury toxicity or had shown any form of hypersensitivity. The only changes found in the exposed workers, compared with the controls, were a reduction of the cells that express cluster differentiation (CD25,(T activation antigen (Tac antigen))) and concentrations of tumour necrosis factor-alpha (TNF-alpha) in serum. However, the decrease of cells that express CD25 was unrelated to occupational exposure and was, in all likelihood a chance finding. Conversely, the decline in serum TNF-alpha was closely associated with occupational exposure. However, no dose-response relation was found between U-Hg and TNF-alpha concentrations; nor were TNF-alpha concentrations affected by cumulative occupational exposure to inorganic mercury in over 20 years. CONCLUSIONS: Tentatively, we suggest that reduced serum TNF-alpha concentrations might be indicative of an in vivo functional defect of the monocyte macrophage system in this particular group of workers even though they were clinically asymptomatic.

Biomarkers↗
PubMed1996

Assessment of exposure to inorganic arsenic, a human carcinogen, due to the consumption of seafood.

To assess whether regular consumption of seafood, particularly fish and shellfish, by humans may lead to an overexposure to inorganic arsenic, a well-established human carcinogen, the urinary excretion of the relevant As metabolites (Asi, inorganic form; MMA, monomethylarsonic acid; DMA, dimethylarsinic acid) was compared in groups of subjects with different seafood consumption habits and in volunteers after ingestion of a known amount of seafood arsenicals. Studies of Italian cohorts, involving five groups of +/-30 subjects with different seafood consumption habits, and balance studies in Belgian volunteers failed to show a biologically significant absorption of inorganic arsenic either present as such in the food or formed from organoarsenicals during cooking or digestion. The results suggest that the digestion of some seafood, especially mussels, may increase the urinary excretion of the dimethylated arsenic metabolite. Therefore, the biological monitoring of exposure to inorganic arsenic in an industrial context should mainly rely upon specific measurement of the unmetabolized form when recent ingestion of seafood cannot be excluded.

Arsenic↗
PubMed1992

The microdose problem and the most commonly used metals.

On the basis of recent research a relationship may exist between microexposure to metals and certain diseases (e.g. neurological and cardiovascular diseases) which occur in the later stages of life. This fact must be kept firmly in mind in view of the implications for the quality of health, considering the increase in average life expectancy. Moreover, it will be necessary to re-identify the critical organ for each metal, bearing in mind that the effects are altered in low level exposure conditions.

Adult↗
PubMed1990

Mortality from liver disease among Italian vinyl chloride monomer/polyvinyl chloride manufacturers.

The possible association in humans between nonangiosarcoma primary liver tumors (PLC-non-A), particularly hepatocellular carcinoma (HCC), and exposure to vinyl chloride monomer (VCM) is supported by both experimental and human data. This article presents a review of the information regarding 253 deaths that occurred in seven plants manufacturing VCM/PVC and one plant extruding PVC. The retrieval of clinical and pathological data, in addition to the information from death certificate, is referred to as "best evidence" (BE). BE has been carried out for 63 deaths. A total of 14 primary liver cancer (PLC) were detected: seven were angiosarcoma (PLC-A), and two of the remaining seven were hepatocellular carcinoma (HCC). In our series of 14 PLC cases, there was no significant difference between PLC-A and PLC-non-A as to length of exposure and latency. There was no noticeable difference in terms of job title between ASL and non-ASL cases. The list of longest held jobs shows the presence of various job titles, different from autoclave cleaner, for primary liver cancer, PLC-A and PLC-non-A. In conclusion, our observations show that VCM may have a broader carcinogenicity action on the liver and that exposure lower than that occurring in autoclave cleaning can cause primary liver cancer, both angiosarcoma and nonangiosarcoma.

Adult↗
PubMed1988

Effects derived from long-term low-level chromium exposure in ferro-alloy metallurgy. Study of absorption and renal function in workers.

Ferro-chromium production is based on the use of chromium oxide (III) and it is generally accepted that chromium in this form is not able to cross biological barriers. However, the data on the toxic and carcinogenic effects of hexavalent chromium in man are now firmly established. Some studies have questioned these data, calling for a clarification as to whether exposure to trivalent chromium can also produce human effects, perhaps with different latency time. A study was carried out on the exposure conditions (type and degree) in a ferro-chromium foundry that had been in operation since 1972. The absorption levels in the working population of the foundry, and the possible toxic effects on the kidney have been investigated. A total of 236 workers (142 employed in production departments, 33 office workers and 61 sub-contractor employees) were examined with measurement of the indicators of dose (urinary-chromium) and of effect on the kidney (albumin, retinol binding protein, and renal tubular epithelium antigens in the urine). Environmental hygiene measurements showed relatively low values of total chromium in the air (always less than 0.160 mg/m3). Hexavalent chromium was absent or, if present, at levels below the sensitivity of the analytical method used (0.001 mg/m3). The values of urinary chromium measured at the beginning and at the end of the working day and at the end of the work shift were always less than 5 micrograms/g creatinine, which has been proposed as a biological limit in chromium exposure. However, differences were observed between groups of subjects employed on different jobs, which is indicative of an absorption process varying according to the degree of exposure. The indicators of effect did not reveal any renal impairment, even early, that could be attributed to the toxic action of chromium.

Adult↗
PubMed1981

Occupational exposure to polychlorinated biphenyls in electrical workers. I. Environmental and blood polychlorinated biphenyls concentrations.

Industrial exposure to polychlorinated biphenyls (PCBs) and internal dose were investigated in 80 worker exposed for many years to PCB mixtures with a 42% chlorine content (Pyralene 3010 and Apirolio). PCBs were determined by liquid gas chromatography on samples taken from workroom air, workroom surfaces and tools, the palms of the hand, and the blood of the workers. In the workroom air samples, PCB concentrations ranged from 48 to 275 micrograms/m3. All tested surfaces and tools were heavily contaminated, with a range from 0.2 to 159 micrograms PCBs per cm2 of surface. Considerable amounts of PCBs were detected on the palms of the hands of the workers (2-28 microgram/cm2 of skin surface). In blood, total PCB concentrations from 88 to 1319 micrograms/kg were observed: comparing the blood concentrations of low and high chlorine content biphenyls, a significant difference was found for the low-chlorinated biphenyl concentrations between workers currently exposed and workers exposed only in the past. In groups of workers who were homogeneous as regards work area and job, the PCB concentrations in the blood were closely correlated with the length of actual occupational exposure to these compounds. These findings led to the conclusion that absorption of PCBs in these workers had occurred mainly through the skin, therefore industrial preventive surveillance must take this route of exposure into account. Since blood PCB concentrations appear to be correlated with the length of exposure, PCB determination on whole blood may be used to monitor industrial and environmental exposure to PCBs.

Adult↗
PubMed1981

Occupational exposure to polychlorinated biphenyls in electrical workers. II. Health effects.

Health conditions were evaluated in 80 electrical workers exposed for many years to polychlorinated biphenyl (PCB) mixtures with a 42% mean chlorine content, who had blood PCB concentrations from 41 to 1319 micrograms/kg. The clinical study was based on personal history data, physical examination, and laboratory tests (red cell and leukocyte count; determination of haemoglobin, packed cell volume, bilirubin, serum protein electrophoretic fractions, pseudocholinesterase, AST, ALT, GGT, and OCT). Fifteen workers were found to have skin diseases--chloracne (4), folliculitis (4), oil dermatitis (1), juvenile acne (1), and dermatitis due to irritative or allergic agents (5). Sixteen workers showed more or less pronounced hepatic involvement, consisting most often of hepatomegaly with an increase in serum GGT, AST, ALT, and OCT values. In two workers bleeding cavernous haemangiomas were discovered, in one case associated with chronic myelocytic leukaemia. All the workers with chloracne were employed on electric capacitor impregnation with PCBs, and no definite association was found between chloracne and blood PCB concentrations. Conversely, a significant positive association was found between the abnormal liver findings and blood PCB concentrations, particularly trichlorobiphenyl blood concentrations. The abnormal hepatic findings observed are similar to those reported in experimental animals given PCBs, and in some workers such findings should probably be considered as clinical signs of hepatic microsomal enzyme induction.

Adult↗
PubMedDate not supplied

Toxicological and immune findings in workers exposed to pentachlorophenol (PCP).

Pentachlorophenol (PCP) is a pesticide used worldwide in industrial and domestic applications. Data available on the effects of technical-grade PCP on the immune system are insufficient and equivocal; some data indicate inhibitory effects, whereas others suggest stimulating effects. This study was performed to evaluate toxicological and immune findings in 32 subjects who had prolonged exposure to PCP in a wood factory and in 37 controls. PCP concentrations were determined in plasma and urine of all subjects. Lymphocyte subsets of CD3-, CD4-, and CD8-positive cells were evaluated, and the proliferative response of peripheral blood mononuclear cells (PBM) to mitogens was assessed. The results suggested the absence of major laboratory and clinical signs of PCP-dependent immune deficiency. A weak effect of long-term exposure to PCP on the functional immune response could not be ruled out because of the finding of a decreased response to 5% PHA in the high-exposure group. A weak effect against hepatocyte membrane was evidenced by the finding of raised serum concentration of glycocholic, taurodeoxycholic, and glycochenodeoxycholic acids in subjects directly exposed to PCP for more than 10 y.

Adolescent↗