Benzene exposure assessment at indoor, outdoor and personal levels The french contribution to the life MACBETH programme

International audienceMany VOC represent hazards to human health through chronic exposure. Recent European and world-wide legislation proposes limit values for ambient concentrations of these compounds. However, very little experimental data exists for true population exposure. In 1996, the European MACBETH initiative set out to measure population exposure to benzene in six European cities. This study details the French contribution to this program. Six campaigns were carried out, each comprising measurements at 100 outdoor sites and the participation of 50 non-smoking volunteers who wore personal samplers and had passive monitors installed in their homes. Iso-concentration maps were drawn for each campaign and the results showed that outdoor concentrations were significantly lower than indoors. Almost 75% of the volunteers were exposed to mean concentrations higher than the limit value of 5 mu gm(-3). It is demonstrated that personal exposure levels cannot be deduced simply by combining indoor and outdoor background concentrations. It is also shown that there is need for better knowledge of the contributions to overall exposure of outdoor microenvironments and the authors hope that future European directives will take this into accoun

Atmospheric volatile organic compounds monitoring Ozone induced artefact formation

International audienceAssessment of population exposure to VOC in ambient atmospheres is receiving heightened interest as the adverse health effects of chronic exposure to certain of these compounds are identified. Active (pumped) and passive samplers are the most commonly used devices for this type of monitoring. It has been shown, however, that these devices, along with all other preconcentration techniques, are susceptible to ozone interference. It is demonstrated that this interference occurs even at low ozone concentrations and that it may result in the under-estimation of population exposure. A convenient and effective ozone scrubbing method is identified and successfully applied and validated for both active and passive samplers for a range of VO

Ambient volatile organic compound monitoring by diffusive sampling Compatibility of high uptake rate samplers with thermal desorption

International audienceField and laboratory validation studies mere carried out on a novel, high uptake rate, radial diffusive sampler loaded with Carbotrap, a thermally desorbable adsorbent, For field experiments parallel techniques mere employed for comparison, The goal was to assess the compatibility of the device for subsequent thermal desorption and preconcentration of the sample for analysis, Some unexpected results were obtained especially for benzene, where it was observed that, under certain conditions the longer the device was exposed to an atmosphere, the less sample was collected, A possible explanation for these results is put forward by applying knowledge previously acquired on saturation and competitivity effects, An alteration to the sampler geometry is proposed which, through further laboratory and field work, is shown to overcome this problem

Urban benzene and population exposure

International audiencePeople aren't just at risk from carcinogenic benzene when they are out on city streets. Benzene pollution emanating from motor traffic can cause leukaemia with the risk being estimated at about four cases per million among people who experience lifelong exposure to benzene concentrations of 1 micro g m-3 in air. But we show here that personal exposure, and therefore risk estimates, cannot simply be estimated from environmental concentrations of benzene. Using a new sampling device that monitors both of these parameters, we have discovered that people living in different European cities are exposed to concentrations of benzene that may be twice as high as the urban averag

Urban benzene pollution and population exposure

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Abstracts of the 6th FECS Conference 1998 Lectures

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