Isabelle Baldi

Twenty five year mortality and air pollution: results from the French PAARC survey.

Aims and Methods: Long term effects of air pollution on mortality were studied in 14 284 adults who resided in 24 areas from seven French cities when enrolled in the PAARC survey (air pollution and chronic respiratory diseases) in 1974. Daily measurements of sulphur dioxide, total suspended particles, black smoke, nitrogen dioxide, and nitric oxide were made in 24 areas for three years (1974–76). Cox proportional hazards models controlling for individual confounders (smoking, educational level, body mass index, occupational exposure) were applied, and frailty models used to take into account spatial correlation. Indicators of air pollution were the mean concentration. Results: Models were run before and after exclusion of six area monitors influenced by local traffic (NO/NO2 >3 in ppb). After exclusion of these areas, analyses showed that adjusted risk ratios (95% CI) for TSP, BS, NO2, and NO for non-accidental mortality were 1.05 (1.02 to 1.08), 1.07 (1.03 to 1.10), 1.14 (1.03 to 1.25), and 1.11 (1.05 to 1.17) for 10 μg/m3 respectively. Consistent patterns for lung cancer and cardiopulmonary causes were observed. Conclusions: Urban air pollution assessed in the 1970s was associated with increased mortality over 25 years in France.

Association between Parkinson’s Disease and Exposure to Pesticides in Southwestern France

A case-control study was performed in southwestern France in order to assess the relationship between pesticide exposure and Parkinson’s disease (PD) in the elderly. During the period from 1997 to 1999, 84 cases were recruited together with 252 population-based controls. Experts in occupational health reviewed job codes and provided pesticide exposure levels, making it possible to calculate cumulated exposure lifelong for individuals. Environmental pesticide exposure was considered in relation to the place of residence. A positive association was found with occupational pesticide exposure (odds ratio = 2.2, 95% confidence interval 1.1–4.3) in conditional logistic multiple regression analysis taking into account age, sex, educational level and smoking; however, no clear dose relationship was found. Our results support the hypothesis of an association between occupational pesticide exposure and PD and point to the need to investigate the role of fungicides, for which toxicological hypotheses exist.

Mobile phone use and brain tumours in the CERENAT case-control study

The carcinogenic effect of radiofrequency electromagnetic fields in humans remains controversial. However, it has been suggested that they could be involved in the aetiology of some types of brain tumours. Objectives The objective was to analyse the association between mobile phone exposure and primary central nervous system tumours (gliomas and meningiomas) in adults. Methods CERENAT is a multicenter case-control study carried out in four areas in France in 2004–2006. Data about mobile phone use were collected through a detailed questionnaire delivered in a face-to-face manner. Conditional logistic regression for matched sets was used to estimate adjusted ORs and 95% CIs. Results A total of 253 gliomas, 194 meningiomas and 892 matched controls selected from the local electoral rolls were analysed. No association with brain tumours was observed when comparing regular mobile phone users with non-users (OR=1.24; 95% CI 0.86 to 1.77 for gliomas, OR=0.90; 95% CI 0.61 to 1.34 for meningiomas). However, the positive association was statistically significant in the heaviest users when considering life-long cumulative duration (≥896 h, OR=2.89; 95% CI 1.41 to 5.93 for gliomas; OR=2.57; 95% CI 1.02 to 6.44 for meningiomas) and number of calls for gliomas (≥18 360 calls, OR=2.10, 95% CI 1.03 to 4.31). Risks were higher for gliomas, temporal tumours, occupational and urban mobile phone use. Conclusions These additional data support previous findings concerning a possible association between heavy mobile phone use and brain tumours.

Pesticides in Lebanon: a knowledge, attitude, and practice study

Pesticides, despite their known toxicity, are widely used in developing countries. Evaluating the pattern of their use would be interesting to assess the appropriateness of adequate intervention. Using a standardized questionnaire, a knowledge, attitude, and practice study was performed in two Lebanese regions, in which a group of agricultural workers was compared to workers of the general population and a third group of pesticide distributors. Agricultural workers were exposed to pesticides during cropping, mixing, loading, and application (100%). They had low pesticide knowledge scales compared to pesticide distributors and to the general population workers (P<10(-7)). The preventive measures they took were low, and the lower their knowledge was, the lower were the preventive measures applied (P<10(-3)). Pesticide safety education is necessary in order to induce protective behavior among agricultural workers. The general population may also benefit from increasing their awareness regarding pesticides.

Exposure to pesticides and risk of childhood cancer: a meta-analysis of recent epidemiological studies.

Objectives The authors performed a meta-analysis of case–control and cohort studies to clarify the possible relationship between exposure to pesticides and childhood cancers. Methods Two cohort and 38 case–control studies were selected for the first meta-analysis. After evaluating homogeneity among studies using the Cochran Q test, the authors calculated a pooled meta-OR stratified on each cancer site. The authors then constructed a list of variables believed to play an important role in explaining the relation between parental exposure to pesticide and childhood cancer, and performed a series of meta-analyses. The authors also performed a distinct meta-analysis for three cohort studies with RR data. Results Meta-analysis of the three cohort studies did not show any positive links between parental pesticide exposure and childhood cancer incidence. However, the meta-analysis of the 40 studies with OR values showed that the risk of lymphoma and leukaemia increased significantly in exposed children when their mother was exposed during the prenatal period (OR=1.53; 95% CI 1.22 to 1.91 and OR=1.48; 95% CI 1.26 to 1.75). The risk of brain cancer was correlated with paternal exposure either before or after birth (OR=1.49; 95% CI 1.23 to 1.79 and OR=1.66; 95% CI 1.11 to 2.49). The OR of leukaemia and lymphoma was higher when the mother was exposed to pesticides (through household use or professional exposure). Conversely, the incidence of brain cancer was influenced by the fathers exposure (occupational activity or use of household or garden pesticides). Conclusion Despite some limitations in this study, the incidence of childhood cancer does appear to be associated with parental exposure during the prenatal period.

Pesticide contamination of workers in vineyards in France

In order to build tools to quantify exposure to pesticides of farmers included into epidemiological studies, we performed a field study in Bordeaux vineyards during the 2001 and 2002 treatment seasons to identify parameters related to external contamination of workers. In total, 37 treatment days were observed in tractor operators corresponding to 65 mixing operations, 71 spraying operations and 26 equipment cleaning. In all, four operators with backpack sprayers and seven re-entry workers were also monitored. We performed both detailed observations of treatment characteristics on the whole day and pesticide measurements of external contamination (dermal and inhalation) for each operation. The median dermal contamination was 40.5 mg of active ingredient per day for tractor operators, 68.8 mg for backpack sprayers and 1.3 mg for vineyard workers. Most of the contamination was observed on the hands (49% and 56.2% for mixing and spraying, respectively). The median contribution of respiratory route in the total contamination was 1.1%. A cleaning operation resulted in a 4.20 mg dermal contamination intermediate between a mixing (2.85 mg) and a spraying operation (6.13 mg). Farm owners experienced higher levels than workers and lower contaminations were observed in larger farms. The contamination increased with the number of spraying phases and when equipment cleaning was performed. Types of equipment influenced significantly the daily contamination, whereas personal protective equipment only resulted in a limited decrease of contamination.

Brain tumours and exposure to pesticides: a case-control study in southwestern France.

Background: Brain tumours are often disabling and rapidly lethal; their aetiology is largely unknown. Among potential risk factors, pesticides are suspected. Objective: To examine the relationship between exposure to pesticides and brain tumours in adults in a population-based case–control study in southwestern France. Methods: Between May 1999 and April 2001, 221 incident cases of brain tumours and 442 individually matched controls selected from the general population were enrolled. Histories of occupational and environmental exposures, medical and lifestyle information were collected. A cumulative index of occupational exposure to pesticides was created, based on expert review of lifelong jobs and tasks. Separate analyses were performed for gliomas and meningiomas. Results: A non-statistically significant increase in risk was found for brain tumours when all types of occupational exposure to pesticides were considered (OR = 1.29, 95% CI 0.87 to 1.91) and slightly higher but still non-statistically significant when gliomas were considered separately (OR = 1.47, 95% CI 0.81 to 2.66). In the highest quartile of the cumulative index, a significant association was found for brain tumours (OR = 2.16, 95% CI 1.10 to 4.23) and for gliomas (OR = 3.21, 95% CI 1.13 to 9.11), but not for meningiomas. A significant increase in risk was also seen for the treatment of home plants (OR = 2.24, 95% CI 1.16 to 4.30) owing to environmental exposure to pesticides. Conclusions: These data suggest that a high level of occupational exposure to pesticides might be associated with an excess risk of brain tumours, and especially of gliomas.

Incidence of central nervous system tumors in Gironde, France

The incidence of CNS tumors is subject to geographical and temporal variations which are poorly understood. The incidence of these tumors was studied in Gironde, a department of southwestern France with 1,058,911 inhabitants older than 16 years. We recorded any malignant or benign central nervous system (CNS) tumor diagnosed between May 1999 and April 2001 in adults living in Gironde. Three hundred and twenty-nine CNS tumors were diagnosed during the study period. The incidence of CNS tumors in adults was therefore 15.5 per 100,000. Overall, the incidence according to sex was 14.7 for males and 16.2 per 100,000 for females. The incidence rate increased according to age up to 80 years (3.7 per 100,000 for 20–29 years of age to 33.4 per 100,000 for 70–79 years of age) and reduced thereafter for gliomas. Our estimation of the incidence of CNS tumors ranks high among the earlier reports. Further analytic studies are ongoing.

Epidemiology of Multiple System Atrophy: A Prevalence and Pilot Risk Factor Study in Aquitaine, France

We investigated the prevalence of multiple system atrophy (MSA) in Gironde, France, through a network of 120 public and private specialists and assessed the relationship between some environmental factors and MSA in a case-control study involving 50 MSA patients, 50 Parkinson’s disease (PD) patients and 50 healthy controls. The occupational exposure to pesticides was evaluated through a job-exposure matrix. On prevalence day (November 1, 1998), the crude prevalence of MSA in Gironde was 1.94/100,000 inhabitants. We found no significant relationship between occupational exposure to pesticides and MSA. PD patients were significantly less frequently ever-smokers than controls and the same tendency was observed for MSA patients. We also described the clinical features that heralded the disease among this nonselected population.

Brain tumors and hormonal factors: review of the epidemiological literature

BackgroundTo date, the etiology of primary tumors of the central nervous system (mainly gliomas and meningiomas) is poorly understood. The role of sex hormones has been suggested, based on clinical, experimental, biological, and epidemiological data.ObjectiveTo review the epidemiological studies on the relation between hormonal factors and the occurrence of glioma and meningioma, in order to identify new research developments.MethodsArticles published until September 2010 were selected by considering exogenous and endogenous exposures and specific brain tumors. Standardized information was collected from 20 articles: 15 concerning gliomas and 13 meningiomas.ResultsAn increased glioma risk was observed with later menarche and menopause, while a reduced glioma risk was observed with hormone replacement therapy (HRT) and oral contraceptive use, despite duration of use had no effect on risk. Meningioma risk increased after menopause and with HRT use. No clear association was found with pregnancy and breastfeeding.ConclusionResults are globally concordant with the biologic hypothesis assuming that female sex hormones are protective against glioma and may increase the risk of meningioma. However, new epidemiological studies should be conducted in order to confirm these associations and to refine the role of hormonal factors in brain etiology.