Is the water safe for my baby?

Ultra-trace determination of total mercury in Italian bottled waters

Mercury (Hg) is a widespread, highly toxic persistent pollutant with adverse health effects on humans. So far, concentrations below the method detection limit have always been reported by studies on the concentration of mercury in bottled water when determined using instrumental analytical methods. These are often very expensive and are unaffordable for many laboratories. In this work, a less expensive method based on cold vapour atomic fluorescence spectrometry has been employed to determine total mercury (Hg_T) concentrations in bottled natural mineral waters. In all, 255 waters representing 164 different typologies were analysed. They came from 136 springs located in 18 Italian regions. In all samples, Hg_T concentrations were found in the range of sub-nanogram to a few nanograms per litre, well below the National and European regulatory limit (1 μg L^-1). Differences in Hg_T concentrations were related not only to the environmental characteristics of the springs but also to the extent and impact of human activities. Higher concentrations were found in waters coming from regions with former mining and/or natural thermal and volcanic activity. These data allowed us to estimate the mercury intake by population (adults, children and toddlers) from drinkable mineral waters consumption. The mean mercury daily intake was found to be remarkably lower, not only than the provisional tolerable value (1 μg L^-1 according to European and Italian legislation) but also than the estimated provisional tolerable weekly intake (PTWI) value (4 μg kg^-1 body weight) recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

Risk of infectious gastroenteritis in young children living in Québec rural areas with intensive animal farming: results of a case-control study (2004-2007)

This study was designed to evaluate the epidemiology of severe gastroenteritis in children living in Québec rural areas with intensive livestock activities. From September 2005 through June 2007, 165 cases of gastroenteritis in children aged from 6 months to 5 years, hospitalized or notified to the public health department were enrolled, and 326 eligible controls participated. The parents of cases and controls were asked questions about different gastroenteritis risk factors. The quality of the drinking water used by the participants was investigated for microbial indicators as well as for four zoonotic bacterial pathogens (Campylobacter spp, Escherichia coli, Salmonella spp and Yersinia spp) and two enteric parasites (Cryptosporidium spp and Giardia spp). From 134 stool specimen analysed, viruses were detected in 82 cases (61%), while 28 (21%) were found with at least one of the bacteria investigated, and five cases were infected by parasites. Campylobacteriosis was the main bacterial infection (n = 15), followed by Salmonella sp (n = 7) and E. coli O157:H7 (n = 5) among cases with bacterial gastroenteritis. No significant difference was found between cases and controls regarding the quality of water consumed; the frequency of faecal contamination of private wells was also similar between cases and controls. Considering the total cases (including those with a virus), no link was found between severe gastroenteritis and either being in contact with animals or living in a municipality with the highest animal density (4th quartile). However, when considering only cases with a bacterial or parasite infection (n = 32), there was a weak association with pig density that was not statistically significant after adjusting for potential confounders. Contact with domestic, zoo or farm animals were the only environmental factor associated with the disease.

Development and validation of a self-administered questionnaire to measure water exposures in children

OBJECTIVE

To develop and validate a questionnaire to measure water exposures in children.

METHODS

Caregivers of children younger than 18 years old evaluated in a pediatric emergency department completed a self-administered questionnaire with items about the child's exposure to water for drinking (15 items), hygiene (4 items), and recreation (5 items); other beverages (11 items); and other risk factors (11 items). Test-retest reliability was measured by administering the questionnaire to the same respondent within 48 hours. Concurrent validity was measured by having a second caregiver, when available, complete the same questionnaire independently. Agreement of paired responses was calculated by kappa (kappa) for categorical variables or Spearman rho (rho) correlation coefficient along with percentage mean difference for continuous variables.

RESULTS

Ninety-four initial surveys were completed (45 subjects with diarrhea). All 94 completed retesting, while 23 had a second independently completed survey. Test-retest reliability (kappa or rho>0.6) was acceptable for 84% of items, and concurrent agreement was acceptable (kappa or rho>0.5) for 91% of items.

CONCLUSIONS

This questionnaire has excellent test-retest and concurrent validity in measuring water exposures and other risk factors for gastrointestinal illness in children.