Urinary arsenic concentrations and speciation in residents living in an area with naturally contaminated soils.

A cross sectional study was carried out to evaluate arsenic exposure of residents living in an area with a soil naturally rich in arsenic (As), through urinary measurements. During the summer of 2007, 322 people aged over 7 years and resident in the study area for at least 4 days prior to the investigation were recruited. The sum of urinary inorganic arsenic and metabolites (iAs+MMA+DMA) and speciation were determined by graphite furnace atomic absorption spectrometry and high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry, respectively. Geometric means levels of iAs+MMA+DMA were 3.6 microg/L or 4.4 microg/g creatinine. The percent of DMA, As(III) and MMA contribution to urinary arsenic concentrations was respectively 84.2%, 12% and 3.7%. We found significant associations between urinary arsenic concentrations and the consumption of seafood (p=0.03), the consumption of wine (p=0.03) and beer (p=0.001), respectively 3 and 4 days before the investigation. When we focus on the various species, As(V) was rarely detected and DMA is the predominant metabolite composing the majority of measurable inorganic-related As in the urine. Considering the percent of DMA contribution to iAs+MMA+DMA urinary concentrations, almost half of the subjects had 100% of DMA contribution whatever the concentration of urinary As whereas the others had a lower DMA contribution, between 39 and 90%. Arsenic levels reported in this original study in France were between 2 and 4 times lower than in other studies dealing with iAs+MMA+DMA levels associated with soil arsenic exposure. Arsenic levels were similar to those observed in unexposed individuals in European countries, although 10% were above the French guideline values for the general population.

Lessons learned from ten investigations of waterborne gastroenteritis outbreaks, France, 1998-2006.

Ten outbreaks of waterborne acute gastroenteritis (AGE) have been investigated in France since 1998. These outbreaks have affected populations of over 1,000 people, with generally high attack rates. The causal agents have been identified in six of these events. Aetiologies involved mainly noroviruses and Cryptosporidium sp. The point of entry of the contamination was located in the distribution network in five outbreaks (waste water backflows in four cases and one case of contamination induced by maintenance work) and at the water collection facilities in five other cases. Once the outbreak was detected, epidemiological and environmental investigations and crisis management followed well-established procedures. Further progress in public health surveillance will depend on more complete and rapid detection and reporting. Automated analysis of health insurance data on the reimbursement of drugs for AGE should help make detection more complete. Improved reactivity depends primarily on the operator immediately reporting incidents that indicate a possible massive contamination of the water network to health authorities - in particular complaints from the population, which are the only early-warning alerts in the case of waste water backflows.