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Biomedical subjects

Emanuela Fadda

Publications and source records attributed to Emanuela Fadda.

10 recordsLinked to original sources

Contrasting patterns of hospital admissions and mortality during heat waves: are deaths from circulatory disease a real excess or an artifact?

In old subjects exposed to extreme high temperature during a heat wave, studies have consistently reported an excess of death from cardio- or cerebro-vascular disease. By contrast, dehydration, heat stroke, acute renal insufficiency, and respiratory disease were the main causes of hospital admission in the two studies carried out in elderly during short spells of hot weather. The excess of circulatory disease reported by mortality studies, but not by morbidity studies, could be explained by the hypothesis that deaths from circulatory disease occur rapidly in isolated people before they reach a hospital. Since the contrasting patterns of hospital admission and mortality during heat waves could also be due to chance (random variation over time and space in the spectrum of diseases induced by extreme heat), and bias (poor quality of diagnosis on death certificate and other artifacts), it should be confirmed by a concurrent study of mortality and morbidity. Many heat-related diseases may be preventable with adequate warning and an appropriate response to heat emergencies, but preventive efforts are complicated by the short time interval that may elapse between high temperatures and death. Therefore, prevention programs must be based around rapid identification of high-risk conditions and persons. The effectiveness of the intervention measures must be formally evaluated. If cardio- and cerebro-vascular diseases are rapidly fatal health outcomes with a short time interval between exposure to high temperature and death, deaths from circulatory disease might be an useful indicator in evaluating the effectiveness of a heat watch/warning system.

Artifacts↗

Lung cancer risk: effect of dairy farming and the consequence of removing that occupational exposure.

The aim of this study was to confirm the exposure-dependent reduction in lung cancer risk reported for dairy farmers exposed to endotoxin and to evaluate the consequence of leaving dairy farming and taking employment in industry or services, where exposure to microbial agents is lower. Standardized mortality ratios, with 95% confidence intervals, for 2,561 self-employed dairy farmers were estimated, considering the general population of Veneto, Italy, from 1970 to 1998 as the reference. Sixty-two lung cancer cases, whose information was checked against clinical records, were compared with 333 controls in a cohort-nested case-control study. Odds ratios with 95% confidence intervals were estimated by logistic regression analysis. A downward trend of standardized mortality ratios for lung cancer across tertiles of number of dairy cattle on the farm was significant (p < 0.05) from 1970 to 1984 but not from 1985 to 1998, when most subjects were no longer dairy farmers. Age- and smoking-adjusted odds ratios for lung cancer significantly decreased with increasing number of dairy cattle (p for trend = 0.001) for workers for whom < or =15 but not >15 years had elapsed from the end of work to the end of follow-up. In conclusion, increased levels of endotoxin (or other associated environmental factors) might be protective against lung cancer; protection diminishes over time after that exposure is removed.

Adult↗

Increased cancer risk among surgeons in an orthopaedic hospital.

BACKGROUND: Five cancer cases over 7 years were reported in a small orthopaedic hospital where radiation protection practice was poor. AIM: To investigate whether workers subject to routine radiation dosimetric assessment in that hospital had an increased cancer risk. METHODS: One hundred and fifty-eight workers subject to routine dose assessment and 158 age-sex-matched unexposed workers were questioned about cancer occurrence. All tumours were analysed as a single diagnostic category. RESULTS: Cumulative 1976-2000 cancer incidence was 29 (9/31), 6 (8/125) and 4% (7/158) in orthopaedics, exposed other than orthopaedics, and unexposed workers, respectively. At logistic regression analysis, working as orthopaedic surgeon significantly (P<0.002) increased the risk of tumours. CONCLUSION: These findings caution against surgeons' underestimation of the potential radiation risk and insufficient promotion of safe work practices by their health care institutions.

Epidemiologic Methods↗

Increased risk of hepatocellular carcinoma and liver cirrhosis in vinyl chloride workers: synergistic effect of occupational exposure with alcohol intake.

Hepatocellular carcinoma (HCC) and liver cirrhosis (LC) are not well-established vinyl chloride monomer (VCM)-induced diseases. Our aim was to appraise the role of VCM, alcohol intake, and viral hepatitis infection, and their interactions, in the etiology of HCC and LC. Thirteen cases of HCC and 40 cases of LC were separately compared with 139 referents without chronic liver diseases or cancer in a case-referent study nested in a cohort of 1,658 VCM workers. The odds ratios (ORs) and the 95% confidence intervals (CIs) were estimated by common methods and by fitting models of logistic regression. We used Rothman's synergy index (S) to evaluate interactions. By holding the confounding factors constant at logistic regression analysis, each extra increase of 1,000 ppm times years of VCM cumulative exposure was found to increase the risk of HCC by 71% (OR = 1.71; 95% CI, 1.28-2.44) and the risk of LC by 37% (OR = 1.37; 95% CI, 1.13-1.69). The joint effect of VCM exposure above 2,500 ppm times years and alcohol intake above 60 g/day resulted in ORs of 409 (95% CI, 19.6-8,553) for HCC and 752 (95% CI, 55.3-10,248) for LC; both S indexes suggested a synergistic effect. The joint effect of VCM exposure above 2,500 ppm times years and viral hepatitis infection was 210 (95% CI, 7.13-6,203) for HCC and 80.5 (95% CI, 3.67-1,763) for LC; both S indexes suggested an additive effect. In conclusion, according to our findings, VCM exposure appears to be an independent risk factor for HCC and LC interacting synergistically with alcohol consumption and additively with viral hepatitis infection.

Aged↗

Endotoxin exposure and lung cancer mortality by type of farming: is there a hidden dose-response relationship?

Previous studies have suggested that those in occupations exposed to endotoxin have a reduced rate of lung/respiratory cancer. An initial investigation found a significantly reduced risk of all sites malignant neoplasms in white male crop and livestock farmers, and black male and female crop farmers. This study provides data on lung/respiratory cancers in the same workers. Data were obtained from occupation and industry-coded US death certificates collected from 26 states for the period 1984-1993. Cause, sex, and race specific proportionate mortality ratios (PMRs) were calculated using a National Institute of Occupational Safety and Health computer program. A pooled relative risk (PRR) was obtained by summing up separately and then dividing the sex-race specific observed and expected cases, separately in crop and livestock farmers. Deaths from respiratory cancer were 12,482 and 2,290, and deaths from lung cancer were 12,091 and 2,201. In each sex and race group respiratory and lung cancer PMRs are generally lower than unity. Lung cancer PRR was 0.80 (0.78-0.81) in crop farmers and 0.70 (0.67-0.73) in livestock farmers, a significant difference (p < 0.0001). Comparison of our findings with those by Nieuwenhuijsen et al. [1999] reporting personal exposure measurements in groups of Californian farmers (endotoxin averaging 132.5 EU/m(3) during livestock farming against 19.9 EU/m(3) during field crop and fruit farming), suggests a decreasing lung cancer risk with increasing endotoxin exposure, and supports a possible dose-response relationship between the two.

Agricultural Workers' Diseases↗

Exposure to diesel exhaust enhances total IgE in non-atopic dockers.

OBJECTIVES: Diesel exhaust particles (DEPs) containing polycyclic aromatic hydrocarbons stimulate the formation of IgE in humans following single and acute exposure. The aim of the present study was to ascertain whether long-standing occupational exposure to DEPs carries a risk of enhanced serum IgE, and of rhinitis or asthma. METHODS: In this cross-sectional study, findings in 76 dockers were compared with those in 63 reference subjects. Among the dockers, drivers and laborers were exposed to diesel emission from forklifts or trucks in the ship-holds, where benzopyrene levels averaged 4.9 ng/m(3). Serum IgE levels were measured by the UNICAP method. Atopy, an evident source of high IgE levels, was assessed by the Phadiatop test. The subjects' clinical and occupational histories were collected. Interval variables were analyzed with Student's t- and Levene's F-tests. The odds ratio (OR) with the 95% confidence interval (CI) was obtained by the exact method at univariate and multivariate (logistic regression) analysis. RESULTS: In view of the large difference in serum IgE (P=0.00001) and the prevalence of respiratory diseases ( P=0.009) between atopic and non-atopic subjects, we analyzed their data separately. For non-atopic subjects, the risk of presenting high IgE was significantly higher (OR=11.4; CI=1.44-526; P=0.013) and the risk of respiratory disease was significantly lower (OR=0.09; CI=0.00-0.73; P=0.016) in drivers and laborers as a whole than in the reference subjects. None of the ORs was significant among atopic individuals. CONCLUSIONS: In non-atopic dockers, long-standing exposure to DEPs at concentrations similar to those in heavily polluted cities increased serum IgE levels but not the incidence of rhinitis or asthma.

Adult↗

Epidemiologic evidence of cancer risk in textile industry workers: a review and update.

A meta-analysis of epidemiologic studies for textile industry workers was undertaken in an attempt to evaluate whether the cancer risk varies within the textile industry in relation to the job held or the textile fiber used. We combined studies published up until 1990, when an ad hoc IARC Monograph was issued, and those published after 1990 with the aim of appreciating evidence of reversing trends in cancer risk. Observed and expected cases reported in the original studies were summed up and the totals were divided to obtain a pooled relative risk (PRR) with a 95% confidence interval (CI) estimated with a fixed-effect model. We calculated a chi-square test (chi2) of heterogeneity among studies. When PRR and chi2 were both significant, PRR and CI were calculated with a random-effect model and the source of heterogeneity was investigated. Lung cancer risk was around 0.4 in the first study on cotton workers published in 1936, around 0.7 in subsequent studies, mostly published in the 1970s and 1980s, and around 1.0 in the last studies published in the 1990s. Papers published in the 1970s and 1980s produced consistent risk estimates for lung cancer risk, which was significantly lower than 1.0 in workers exposed to cotton (PRR = 0.77; CI = 0.69-0.86) and wool dust (0.71; 0.50-0.92), as well as in carders and fiber preparers (0.73; 0.54-0.91), weavers (0.71; 0.56-0.85), and spinners and weavers (0.78; 0.66-0.91). Lung cancer PRRs did not significantly deviate from 1.0 in textile workers using synthetic fibers or silk, and in dyers. Increased PRRs were found for sinonasal cancer in workers exposed to cotton dust, and in workers involved in spinning or weaving (4.14; 1.80-6.49). PRR was 1.46 (1.10-1.82) for cancer of the digestive system in textile workers using synthetic fibers or silk, and 1.34 (1.10-1.59) for colorectal cancer in spinners and weavers. The increased bladder cancer PRR in dyers (1.39; 1.07-1.71) is generally attributed to textile dye exposure. In studies published after 1990, there is a general tendency to move toward unity for all the cancer risk estimates, leading to an increasing heterogeneity among studies. Since adjustment for smoking made little difference to the findings, the latter could be attributed to the exposure to textile dusts. The recent findings could be due to a lowering of dust concentration in the workplaces. The reduction of cases of upper respiratory tract cancer parallels with a corresponding increase of lung cancer cases. So, preventive measures have paradoxically increased the lung cancer burden to the textile workers.

Adult↗

[Occupational chronic obstructive pulmonary disease: Italian law (decree no. 336/1994) and epidemiological evidence].

BACKGROUND: In Italy, occupational diseases are required by law to be listed (however, any occupational diseases not included in the list may be compensated if workers demonstrate causation in court). The list is periodically updated in order to incorporate new findings from medical research. Decree no. 336/94 uses a less inclusive term (chronic obstructive bronchitis) than that used in the earlier decree, no. 482/75 (chronic obstructive pulmonary disease, COPD). Moreover, it includes fewer occupations that involve a risk of developing COPD. OBJECTIVES: In order to find an epidemiological basis that might justify the above changes to Italian law, risk of COPD was investigated in relation to occupation and time, using a case-referent design. METHODS: The same definition for COPD (clinical history of >2 years with shortness of breath and/or winter phlegm and an FEV1 less than 80% of the predicted value, only minimally reversible with bronchodilators and without marked change during the hospital observation period) was used in two case-referent studies. The first study was carried out from 1972 to 1980 (202 cases of COPD and 202 referents matched for age and sex) and the second from 1990 to 1997 (131 cases of COPD and 298 referents, every fourth eligible patient in each calendar year of observation). In both studies cases and referents were classified into 16 occupational categories, and office workers were the reference. All subjects were selected from male patients admitted to the Occupational Health Clinic in Padua. Smoking-adjusted (Mantel-Haenszel analysis, first study), or age-smoking-adjusted (logistic regression analysis, second study) Odds Ratio (OR) and 95% confidence interval (CI) for COPD were estimated in each occupational category and in two main groups: workers employed in occupations at either high or low risk for COPD. The latter OR and the fraction of exposed cases (pc) were used to estimate the population attributable risk (PAR) through: pc(OR-1)/OR. RESULTS: Significantly high risks for COPD in miners and chemical workers were observed in the first period, but not in the second time window. On the other hand, an increased time trend for OR estimates was found in welders, wood carpenters, construction and foundry workers. Among farmers, painters, cotton textile and refractory brick workers, the OR for COPD was significantly above unity in both time periods. PAR was 37% in the first and 52% in the second study. CONCLUSIONS: The restrictive definition of occupational COPD, which was introduced by Decree no. 336/94, contrasts with the epidemiological evidence showing that the risk of occupational COPD has increased over time: up to 50% of COPD cases referred to an occupational medicine physician might have an occupational origin.

Adult↗