PubMed Health⌕ Search

Biomedical subjects

C Zocchetti

Publications and source records attributed to C Zocchetti.

At least 19 recordsLinked to original sources
PubMed1992

Mortality of a young population after accidental exposure to 2,3,7,8-tetrachlorodibenzodioxin.

The mortality experience of 19,637 people aged 1-19 years living in an area around Seveso, Italy, contaminated by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) after an accidental explosion in a chemical plant was examined for the period 1976-1986. For comparison, the mortality of the population of nearly 100,000 people living in the surrounding districts was examined. People who left the study area were followed up. Vital status ascertainment was successful in over 99% of the cases. A group of 186 children who contracted chloracne, a reversible marker of TCDD intoxication, shortly after the accident were in the study: none of them died during the observation period. Among the exposed, mortality owing to all causes, to all accidents and to all cancers failed to show major departure from expectations. Five leukaemia deaths were observed, four among males and one among females; the corresponding relative risks were 2.1 (95% confidence interval (CI): 0.7-6.9), and 2.5 (95% CI: 0.2-27.0), respectively. Two lymphatic leukaemias among males yielded a RR = 9.6 (95% CI: 0.9-106.0). Mortality owing to congenital anomalies showed a nearly twofold increase in the contaminated area; however, five out of seven observed cases were born before the accident. Interpretation is limited by the small number of deaths, short latency period and low validity of death certificate information for certain causes, and by the definition of exposure which was based merely on residence. The follow-up is continuing. A cancer morbidity study is in progress.

Adolescent↗
PubMed1989

Mortality study of cancer risk among oil refinery workers.

The mortality experience of 1595 male workers employed in one of the largest Italian refineries in the period from 1949-1982 was examined. From the comparison with national and local death rates, increases in mortality owing to lung and kidney cancers, brain tumors, and leukemias emerged. No definite trends according to duration of exposure and years since first exposure were apparent. The increases regarding cancer of the lung, kidney and brain appeared to be associated with the early period of operations. Analysis by exposure category suggested an association of the increased mortality from leukemias with working in production (observed = 2; expected = 0.61). Kidney cancer mortality was elevated among maintenance workers (obs. = 2; exp. = 0.18). Small numbers prevented firmer conclusions. Workers in the moving department had a significantly increased mortality from all cancers (obs. = 22; exp. = 11.7), and lung cancer (obs. = 11; exp. = 3.6). Confounding by smoking could be excluded as sufficient explanation of the three-fold increase in lung cancer deaths. It was in moving that highest airborne levels of polynuclear aromatic hydrocarbons had been discovered in an independent environmental investigation.

Adolescent↗
PubMed1989

Ten-year mortality study of the population involved in the Seveso incident in 1976.

In 1976, an accidental explosion in a plant near Seveso, Italy, caused the contamination of a populated area by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The area was subdivided into three zones (A, B, and R) having decreasing mean levels of TCDD soil contamination. This study examines the mortality between 1976 and 1986 among the subjects, aged 20-74 years, who were resident in the area since the accident (n = 556 in zone A, n = 3,920 in zone B, n = 26,227 in zone R). Subjects' exposure was classified by residence. A referent cohort of 167,391 subjects who lived in the immediate surroundings was concurrently examined. Vital status ascertainment was successful for over 99% of the subjects. Increased mortality from cardiovascular causes was found; incident-related stressors were considered more relevant to increased mortality than was TCDD exposure. Mortality from several cancers was elevated. The increases in biliary cancer (females), brain cancer, and lymphatic and hemopoietic neoplasms (particularly leukemia in males) did not appear to result from chance, confounding, or information/comparison bias. However, no definite patterns related to exposure classification were apparent. Merely suggestive increases in soft tissue tumors and melanoma were also noted. Liver and breast cancer mortality tended to be below expectations. Interpretation is hampered by the short observation period, small number of deaths from certain causes, and poor exposure definition. Further research is in progress.

Accidents, Occupational↗
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↗
PubMed1987

Cancer mortality of capacitor manufacturing workers.

Experimental studies have demonstrated that certain types of commercially produced polychlorinated biphenyls (PCBs) are carcinogenic. Data in humans are still controversial. This study was undertaken in order to determine possible long-term effects, particularly cancer, in workers engaged in the manufacture of capacitors impregnated with PCBs in a plant operating since 1946. All workers employed for at least 1 week between 1946 and 1978 were admitted to the study (544 males and 1,556 females), and their mortality was examined for the period 1946-1982. Data on environmental contamination, workers' PCBs intake, and health effects (chloracne) were available, which documented the general exposure conditions in the plant. Vital status was ascertained for over 99% of the subjects, and death certificates were obtained for all deceased persons. Expected deaths were calculated using two sets of mortality rates, national and local. Among male workers, cancer deaths (14 obs.) were significantly increased as were deaths owing to cancer of the gastrointestinal (GI) tract (6 obs.). Also, mortality from hematologic neoplasms (3 obs.) and lung cancer (3 obs.) was higher than expected; however, the excess was statistically not significant. Female workers exhibited an overall mortality that was significantly increased above expectations. Cancer deaths (12 obs.) and hematologic neoplasms (4 obs.) were significantly higher than expected when compared with the local population. Interpretation of the results is limited by the small number of deaths; however, the point of interest is the consistency of these results with previous experimental and epidemiologic studies, which indicated the GI tract and lymphatic and hemopoietic tissue as the most probable target sites of the PCBs carcinogenic activity.

Digestive System Neoplasms↗
PubMed1986

Exposure to formaldehyde and cancer mortality in a cohort of workers producing resins.

The mortality of 1,332 male workers employed at least 30 days in 1959-1980 in a resins-manufacturing plant was examined. Ambient measurements taken in the plant between 1974 and 1979 documented a potential for exposure to levels of formaldehyde as high as greater than 3.0 mg/m3. Vital status was ascertained for 98.6% of the cohort members, and their mortality was compared with expected deaths drawn from the national and local population rates. A statistically significant increase in lung cancer was observed, based on 18 deaths, which was not fully accounted for by possible confounding factors linked to personal habits or sociocultural characteristics. This elevated risk, however, could not be attributed specifically to exposure to formaldehyde. Mortality from digestive cancer (14 deaths observed) and hematologic neoplasms (5 deaths observed) was not substantially higher than expected. The study was limited by information bias due to incomplete work histories, by the small number of deaths from some relevant causes, and by the possibly insufficient length of the observation period. Therefore these results do not provide sufficient grounds either to link formaldehyde exposure in the plant to the increased cancer risk noted or to exclude that formaldehyde might pose such a risk to humans under certain exposure circumstances.

Adolescent↗
PubMed1986

Cancer mortality of an Italian cohort of workers in man-made glass-fiber production.

This study was undertaken in order to examine possible long-term effects, particularly cancer, associated with working in the man-made glass-fiber production industry in Italy (glass wool and continuous filament). All male production workers employed for a minimum of one year between 1944 and 1974 were admitted to the study (1,098 subjects), and their mortality was examined in the period 1944-1983 (21,325 person-years). The vital status ascertainment was successful for 98.9%, of the cohort members. An increased risk of cancer of the larynx was noted based, however, on only four deaths. When contrasted with the values of the local population, the increase proved to be statistically significant after 25 years since first exposure. The higher than expected larynx cancer mortality was confined to workers hired before the age of 25 years, exposed for at least 15 years, who started exposure before 1960 (main production: glass wool), and who belonged to the highest cumulative exposure categories. Known confounding factors could not completely account for the excess observed. Among the numerous studies carried out on man-made glass-fiber workers, only one incidence study in France support our findings. No other increased cancer risks have been suggested by the present study.

Adult↗
PubMed1985

Behaviour of biological indicators of cadmium in relation to occupational exposure.

Cadmium in blood (CdB), cadmium in urine (CdU) and beta 2-microglobulins (beta 2MU) were determined in 83 male workers exposed to cadmium fumes. CdU was measured both on 24-h urine samples and on spot samples. The behaviour of the biological indicators of cadmium was assessed in relation to degree of current exposure, length of exposure and cumulative exposure (computed as concentration of cadmium at the workplace multiplied by duration of exposure). CdB values were significantly higher in the subgroups of subjects with higher current cadmium exposure and in the subgroups of subjects with greater cumulative exposure, but the test levels were not influenced by duration of exposure. CdU levels were significantly higher in the subgroup of subjects with greater cumulative exposure, but were less influenced by current exposure or duration of exposure. Considering the entire population, a rather close correlation (r = 0.69) was observed between CdB and CdU. When the population was divided according to level of current exposure, a close relationship was observed between the two indicators in all subgroups; nevertheless, for identical CdU values, the CdB values were higher in the subjects with heavier current exposure. Even if in all Cd workers the beta 2MU levels were in the range of reference values, the highest beta 2MU levels were found in the subjects with CdU greater than 10 micrograms/l. The data confirm that CdU is prevalently influenced by the body burden of metal, but they also suggest that the CdB levels are not influenced solely by the intensity of current exposure but also depend to a considerable degree on the body burden.

Adult↗
PubMedDate not supplied

[Medicina del Lavoro. 90 years of a publishing history].

The following piece is meant to widen general knowledge about La Medicina del Lavoro. This is not an analytical history with interpretations and conclusions; it is simply a narration of facts, anecdotes, and details that are often overlooked, and which taken on importance only in retrospect. It is also a pleasurable satisfaction of the author's curiosity, and above all, a tribute to those who ideated and created the journal, people, associations, and printers, thanks to whom the journal, especially during the difficult first years, was able to grow and develop into a specialized tool with a privileged position both in the history of Occupational Medicine in Italy and in the international scientific community. Perhaps the reader will find some imprecise or partial information in this piece, still it has the virtue (at least, such it is deemed) of being based only on what was written in the volumes of the journal; as a matter of choice, no other source was consulted. One needs also to add that the piece dwells prevalently upon the early years of La Medicina del Lavoro, either because they were rich in events or because so many of our current readers are well informed about the recent history of the journal. Finally, since the complete collection of 82 volumes is available to only a few (in particular there is a scarcity of the first few volumes), we have made an enclosure to integrate the bibliographical references with reproductions of some of the more relevant documents.

History, 20th Century↗
PubMedDate not supplied

Mortality in an area contaminated by TCDD following an industrial incident.

The mortality experience of the population, aged 20-74 years, living in an area contaminated by TCDD after an industrial accident in 1976, was examined in the period 1976-1986 and compared with the mortality of the population of the surrounding noncontaminated territory. People who left the area during the study period were followed up, and vital status was successfully ascertained for over 99% of the cohort members. An increased mortality, from chronic ischemic heart disease (males) and hypertensive disease (females), which could not be explained in terms of chance, confounding, or bias, was noted in the exposed population. The stressful experience of the population in the aftermath of the disaster was deemed relevant to the interpretation of these findings. Overall, cancer mortality was not increased. Suggestive increases, however, were seen for melanoma, brain cancer, soft tissue sarcomas and certain hematologic neoplasms, whereas mortality from breast cancer and cancer of the liver was noticeably decreased. Further research is in progress in order to thoroughly investigate the association, if any, of cancer occurrence with TCDD contamination.

Accidents, Occupational↗
PubMedDate not supplied

[Mortality: various measurements compared].

SMR (Standardized Mortality Ratio) is a useful epidemiological measure but it cannot be computed when person-years distributions (denominators) are not available. In this situation PMR (Proportionate Mortality Ratio) and MOR (Mortality Odds Ratio) represent possible alternatives. Definitions of PMR and MOR are presented, and properties and drawbacks of these measures are discussed in relation to SMR's estimates. Fictitious data representing factual situations are used as working examples.

Algorithms↗
PubMedDate not supplied

[Predictability of the anamnesis in pathology of the upper tract of the digestive system. Computerized analysis concerning 1000 subjects submitted to esophagogastroduodenoscopy].

The ability of history taking to predict endoscopically verified pathology of the upper gastrointestinal tract was evaluated in a group of 1000 patients submitted to esophagogastroduodenoscopy (EGDS). The presence of one or more of the following symptoms at the time of EGDS or 4 weeks previously, was considered: epigastric pain, dysphagia, dyspepsia, gastrointestinal bleeding, pyrosis, anorexia and/or weight loss, nausea and/or vomiting. The results of this elaboration showed that the presence of recent symptomatology does not allow differentiation of patients with endoscopically verified pathology from those without it. The presence of an "at risk history" consisting of one or more of the following factors was also evaluated: smoking 10 cigarettes per day, drinking 100 g alcohol per day, previous diagnosis of upper gastrointestinal tract pathology, gastrointestinal-irritating therapy. Data analysis showed notable importance of the presence of an "at risk history"; in fact, when compared with subjects without this type of history, "at risk" patients were twice as likely to have a pathological condition diagnosed. Thus, when protocols for endoscopic examination are established the history of the patient and his lifestyle must be taken into consideration.

Adult↗
PubMedDate not supplied

[Biological limits of exposure: evolution of interpretative and methodologic criteria].

Biological monitoring is an extremely efficient investigation tool in evaluation of exposure to exogenous substances, in both occupational and environmental settings. However, although biological tests have been widely acclaimed as the ideal approach to or as a completion of environmental measurements, they have had difficulty in becoming firmly established due to a number of limitations of various nature. Besides the numerous uncertainties in the set-up phase, which depend on the choice of indicators or criteria for their use, difficulties are still incurred in making a univocal interpretation of the results. These difficulties are due to the limited pharmaco-kinetic information available on the various substances and to the wide variability in individual biological response. The possibility of extrapolating Biological Exposure Limits (BELs) from the corresponding TLV-TWA, by means of calculations based on the experimental regressions observed between internal and external dose indices, has up to now been considered a dubious operation from a formal point of view and merely indicative for practical purposes. This paper examines the possibility of establishing BELs that are fixed taking account of the influence of the various biological variables, thus permitting a more correct, objective and generalised use of biological indicators in current practice. From the regression function and relative tolerance limits, intended as a range of values within which regression values can be expected to be found with a probability that can be fixed a priori, it is possible to calculate 3 BEL values for each environmental TLV-TWA concentration. The question of which of these different values should be selected as a BEL for practical purposes must be solved on the basis of a series of observations related to the type of investigation being performed and the context in which the results are to be used. It should be emphasized that each BEL value has its own particular sensitivity and specificity, i.e., the possibility of correctly classifying the exposure conditions in relation to the environmental values. If sensitivity and specificity values are known, it is possible to calculate the predictive value of the biological measurements compared to the environmental measurements; if numerical data on these parameters are available, account can be taken of the variability of the results in a rigourously scientific manner.(ABSTRACT TRUNCATED AT 400 WORDS)

Air Pollutants, Occupational↗
PubMedDate not supplied

[Carcinogenic risk for resin producers exposed to formaldehyde: extension of follow-up].

A significant increase in lung cancer was observed in a previous study on the mortality experience of a cohort of 1332 male workers employed between 1959 and 1980 in a resin manufacturing plant. Due to the limited exposure and an inadequate follow-up, it was not possible to make a thorough analysis of the potential association of this elevated risk with exposure to formaldehyde. The study was therefore continued and extended for a further six years (1980-1986), in order to overcome the limitations. Despite these attempts, however, there were still 219 workers whose specific exposure could not be identified. Lung cancer risk in the whole cohort (27,202 person-years) was equal to that of the local population (observed = 24; expected = 23.9). Among those definitely exposed to formaldehyde, 6 lung cancer cases were observed and 8.7 were expected, while those with non-specified exposure exhibited an increase risk (observed = 9; SMR = 211); they were mainly short-term workers employed at the beginning of operations. The previously suggested increase in haematologic neoplasms was confirmed (observed = 7; SMR = 143); the risk was highest among formaldehyde-exposed workers (observed = 3; SMR = 173). Five deaths due to primary liver cancer were observed, while 2.0 would have been expected from the local population rates (SMR = 244); the increased risk was fairly evenly distributed across the exposure categories (exposed to formaldehyde, SMR = 244; non-exposed to formaldehyde, SMR = 227; non-specified exposure = 287); however, all cases were first exposed at the age of 45 years or older. A noteworthy finding was a 50% increase in mortality from respiratory diseases. The increase was mainly apparent among those with longest and earliest exposure, employed in operations classified as involving exposures other than formaldehyde (observed = 9; SMR = 224). Overall, the results of this extended study do not provide sufficient grounds for associating work in formaldehyde resin production in this plant with increased carcinogenic risk; however, limitations in the individual exposure classification and suggestions of an increased risk for certain tumours preclude considering the study as negative. The numerous airborne irritative agents present in the plant environment appeared to have increased the risk of respiratory disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗