C. Sacco

Work related etiology of amyotrophic lateral sclerosis (ALS): a meta-analysis.

BACKGROUND The aim of this meta-analysis was to evaluate the association between ALS and occupational exposure to physical (ELF-EMF) and chemicals (solvents, heavy metals and pesticides) agents. METHODS We considered articles published from 1980 up to April 2013; in total, 750 publications were evaluated. The studies had to satisfy the following criteria: 1) cohort or case-control studies; 2) the presence of individual exposures; 3) clinical diagnosis of sporadic ALS or sporadic ALS on the death certificate. We followed the evaluation of quality in two steps. The first step classified studies according to a rating system based on a mix of criteria developed by scientific organizations, especially developed for studies of risk factors for ALS. The ratings obtained range from I (highest) to V (lowest). The data on risk factors derived from studies with Armon ratings of I, II, and III can reach levels of evidence A (established risk factor), B (likely risk factor), or C (possible risk factor). The second step evaluated the exposure and a score from 1 to 4 was assigned to each item; an exposure with a score of 3 or 4 was considered sufficient. Different analyses were performed on ALS and exposure to metals, solvents, pesticides and electromagnetic fields. In our study the heterogeneity was assessed both by χ2-based Q-tests and through the index of inconsistency I² while the measure RR/OR and CI of 95% to estimate the relationship between ALS and the various considered risk factors was employed. RESULTS The association between exposure to pesticides and ALS as a whole is weak and not significant. With regard to the results of individual studies the following critical synthesis can be reported: 1) the selected studies showed a low level of association between ALS and electromagnetic fields; 2) as regards the solvents, the association with ALS in some studies is combined with a slightly increased risk, particularly in women, and in others a slight but significant linear association is observed; 3) for the metals, in some cases there was a stronger association in women than in men; for individual metals, there was an association especially with chromium and lead; 4) lastly, with regard to the products of agricultural pesticides in general, there was an association with ALS in men but not in women, with a dose-response relationship. CONCLUSIONS The lack of statistically significant association between occupational exposure and ALS is mainly due to the methodological diversity of the studies and the lack of prospective studies at the workplace.

Workers exposed to low levels of benzene present in urban air: Assessment of peripheral blood count variations

BACKGROUND Few studies in the literature have examined the effects of benzene on blood cells. AIM The aim of this study was to evaluate the possible correlation between the blood benzene levels and the blood cell counts. MATERIALS AND METHODS From a population of 2658 workers, we studied a group of 215 subjects. Each worker underwent blood sampling for the assessment of the blood benzene levels and the blood cell counts. The Mann-Whitney U test for two-mode variables and the Kruskal-Wallis test for more-than-two-mode variables were performed on all subjects. We estimated the Pearson correlation index between the variables in the total sample and the subgroups divided according to sex, the smoking habit, and job. After the main confounding factors were evaluated, multiple linear regression was performed on both the total sample and the subgroups. RESULTS A significant inverse correlation was found among the blood benzene levels and the white blood cells, lymphocytes, and neutrophils in traffic policemen, motorcyclists, and other outdoor workers. We did not find any significant correlation with any other parameters of blood cell count. DISCUSSION AND CONCLUSIONS Our results, which must be considered preliminary, indicate that increased blood benzene levels in outdoor workers lead to decreased counts of white blood cells, neutrophils, and lymphocytes, because of possible immune effects. These are worth investigating in the future by specific immune tests.

Correlation Between Cadmium and Blood Counts in Workers Exposed to Urban Stressor

The objective of this study was to assess the exposures to cadmium (Cd) in urban workers and the association between Cd exposure and values of blood counts. Urinary Cd, blood Cd, and blood counts were obtained from 355 outdoor workers; a subgroup of 99 subjects were monitored to evaluate personal exposure to airborne Cd. The mean value of personal exposure to Cd was 1.5 ng/m3 for traffic assistants and 1.2 ng/m3 for drivers. Urinary and blood Cd were correlated to the airborne Cd (respectively r =.3 and r =.4). The multiple linear regression models showed the associations among white blood cell, the percentage of neutrophils (NEU%), the percentage of lymphocytes (LYM%), and the concentrations of blood Cd (respectively R2 =.27, R2 =.37, R2 =.581). The subjects with blood Cd values higher than 1.2 μg/L showed an increase of LYM% mean values and a decrease of NEU% mean values with respect to the group with blood Cd values lower than 1.1 μg/L.

Can noise cause high blood pressure? Occupational risk in paper industry

OBJECTIVES The authors hypothesize cardiovascular effects in paper industry workers exposed to noise. MATERIALS AND METHODS The study included 72 paper industry workers exposed to noise and two control groups not exposed to noise. The workers completed a questionnaire and underwent a medical examination, measurement of blood pressure, electrocardiogram, blood tests, audiometry and measurement of noise exposure. RESULTS The workers exposed to noise, all hearing impaired, were compared with not exposed and showed: significant increase of mean systolic and diastolic blood pressure values (p<0.001), higher frequency of hypertension, systolic and diastolic blood pressure (p<0.01 and p<0.001) and electrocardiografic abnormalities (p<0.05), significant reduction of blood pressure response in orthostatism (p<0.005). CONCLUSIONS Our results suggest that for the workers of the paper industry the noise is an occupational risk factor for cardiovascular effects.

Correlation between urinary cadmium and thyroid hormones in outdoor workers exposed to urban stressors

Objectives: The aim of this study is to evaluate whether exposure to low concentrations of cadmium (Cd) can have effects on the thyroid hormone level of outdoor workers exposed to urban pollutants. Methods: The study was conducted on a final sample of 277 individuals (184 males and 93 females). The environmental monitoring of Cd was evaluated through the use of portable dosimeters, while the biological monitoring was achieved through the assessment of urinary Cd and thyroid hormones. The total sample was divided according to sex and task. The Pearson’s correlation coefficient among the variables was calculated after subdivision on the basis of sex and task. The multiple linear regression was performed to take into account the major confounding factors. Results: Statistical tests showed a negative correlation between urinary Cd levels and free triiodothyronine and free thyroxine and a positive correlation between urinary Cd and thyroid-stimulating hormone levels. Conclusions: Our early results seem to point out that occupational exposure to low concentrations of Cd present in urban air affects the thyroid hormone levels in exposed workers.

Blood pressure changes and polycyclic aromatic hydrocarbons in outdoor workers.

OBJECTIVES Everyday outdoor workers are exposed to chemicals including the polycyclic aromatic hydrocarbons (PAHs). The aim of the study is to evaluate the relationship between hydroxypyrene and blood pressure in outdoor workers. MATERIALS AND METHODS 374 subjects of both sexes entered the study. We evaluated the assay of urinary hydroxypyrene (1-HOP); their blood pressure (BP) was measured in upright position and in the supine position and the correlation between the levels of 1-HOP and BP was assessed using Pearson test and linear multiple regression. RESULTS The results obtained show that in the total sample the levels of urinary 1-OHP are negatively associated with systolic and diastolic BP in supine position and in upright position. The significance is maintained despite the stratification of the sample according to age; in non-smokers we found a negative relationship between 1-OHP and differential blood pressure, both systolic and diastolic. CONCLUSIONS The results of the study suggest that occupational exposure to PAHs may be able to significantly influence the blood pressure probably acting on the autonomic nervous system.

Distortion-product otoacoustic emissions in workers exposed to urban stressors

ABSTRACT The study aimed to compare the distortion-product otoacoustic emissions (DPOAEs) with the pure-tone audiometry and to analyze the changes in participants exposed to noise. The results show a prevalence of participants with impaired DPOAEs higher than the prevalence of participants with impaired audiometries in the total sample, in men, and in outdoor workers and a prevalence of impaired DPOAEs and of impaired audiometries in men higher than in women and in outdoor workers higher than in indoor workers. The comparison of mean values between outdoor and indoor workers shows a significant difference only on some frequencies, in the DP-gram. The results suggest a higher effectiveness of DPOAEs compared with the pure-tone audiometry in identifying the presence of any damage in individuals exposed to noise at an early stage.

Esposizione ad inquinanti urbani e riflessi barocettivi posturali

OBJECTIVE Outdoor workers are daily exposed to urban pollutants. The aim of the study is to evaluate the relationship between the values of environmental monitoring collected by personal dosimetries and changes in blood pressure due to posture in outdoor workers. MATERIALS AND METHODS 32 subjects of both sexes were enrolled in the study, we evaluated the values of environmental monitoring of breathable dust, nickel, arsenic, cadmium, lead, benzene, toluene, xylene and 16 PAHs. Blood pressure in supine and standing positions was measured in all subjects. RESULTS The multiple linear regression analysis showed a significant reduction of orthostatic response of diastolic blood pressure in non-smoking outdoor workers occupationally exposed to cadmium. CONCLUSIONS The results of our study let us to believe that exposure to low doses of urban polluted cadmium may affect the response of diastolic blood pressure to orthostatism, as per a paraphysiological condition of sympathetic down-regulation.

Workers of the printing industry and hepatic damage.

BACKGROUND Typesetting industry is still the primary instrument of communication, despite the development of new technological systems. This study focuses on the analysis of the hepatic effects induced by the use of some organic solvents employed in the printing industry. METHODS We studied a group of 194 workers: 93 exposed and 101 not exposed. The level of the exposure to chemical pollutants were assessed through the environmental monitoring of blood concentrations and the analysis of airborne substances. The health survey was performed through the collection of the medical history and the use of hepatic tests, which were evaluated by calculating Mean, Standard Deviation, Students t-test and X² test with Yates Correction, to investigate statistically significant differences in some hepatic parameters: AST, ALT, ALP, GGT, fractional and total bilirubin. The environmental data sometimes exceeded the TLV-TWA. RESULTS The clinical evaluation of the hepatic parameters showed statistically significant differences as to the hematic concentrations of AST, ALT, GGT. CONCLUSIONS The results we obtained support the hypothesis of a risk among the printing industrial workers attributable to the hepatotoxic solvents. This risk seems to be related to the use of a mixture of solvents, although at low doses, and the analysis of the results obtained confirms the validity of the investigation for the health screening protocol adopted in order to identify subjects and/or population at risk of hepatotoxicity.

Urinary hydroxypyrene and estradiol in an occupationally exposed "outdoor" population.

BACKGROUND Polycyclic aromatic hydrocarbons (PAHs) are widely present in the air pollution. The urinary hydroxypyrene (1-HOPu) is considered the main biological biomarker currently available to measure the exposure to PAH. It is supposed responsible of an increase of estradiol levels in males. Aim of this study is to verify whether there is a relation between 1-HOPu and plasmatic estradiol in non-smoker male workers. METHODS The study was conducted on a sample of 122 non-smoker policemen in a large Italian city; we monitored their levels of 1-HOPu and the values of estradiol. The sample was divided into three groups according to the levels of urinary hydroxypyrene. The indices of correlation (r) and multiple linear regression (β), between levels of 1-HOPu and estradiol were calculated. It was also calculated the students t-test among the groups to check the differences. RESULTS We found statistically significant correlations and multivariate linear regressions between 1-HOPu and estradiol in the total sample and in group III (levels of 1-HOPu above the 75th percentile). The average levels of estradiol in group III was statistically and significantly higher than in the group I (levels of 1-HOPu below the 25th percentile) and group II (levels 1-HOPu between 25th and the 75th percentile). CONCLUSIONS 1-HOPu in non-smoker male workers is related with an increase of plasmatic estradiol. We believe that PAHs, of which 1-HOPu is the main biomarker, can interact with the hypothalamic-pituitary axis. The preliminary results suggest that the topic needs further research on male and female as well.