Screening for Elevated Blood Lead Levels in Children: Assessment of Criteria and a Proposal for New Ones in France.

The decline in children's Blood Lead Levels (BLL) raises questions about the ability of current lead poisoning screening criteria to identify those children most exposed. The objectives of the study were to evaluate the performance of current screening criteria in identifying children with blood lead levels higher than 50 µg/L in France, and to propose new criteria. Data from a national French survey, conducted among 3831 children aged 6 months to 6 years in 2008-2009 were used. The sensitivity and specificity of the current criteria in predicting blood lead levels higher than or equal to 50 µg/L were evaluated. Two predictive models of BLL above 44 µg/L (for lack of sufficient sample size at 50 µg/L) were built: the first using current criteria, and the second using newly identified risk factors. For each model, performance was studied by calculating the area under the ROC (Receiver Operating Characteristic) curve. The sensitivity of current criteria for detecting BLL higher than or equal to 50 µg/L was 0.51 (0.26; 0.75) and specificity was 0.66 (0.62; 0.70). The new model included the following criteria: foreign child newly arrived in France, mother born abroad, consumption of tap water in the presence of lead pipes, pre-1949 housing, period of construction of housing unknown, presence of peeling paint, parental smoking at home, occupancy rates for housing and child's address in a cadastral municipality or census block comprising more than 6% of housing that is potentially unfit and built pre-1949. The area under the ROC curve was 0.86 for the new model, versus 0.76 for the current one. The lead poisoning screening criteria should be updated. The risk of industrial, occupational and hobby-related exposure could not be assessed in this study, but should be kept as screening criteria.

Environmental determinants of different blood lead levels in children: a quantile analysis from a nationwide survey.

Blood lead levels (BLLs) have substantially decreased in recent decades in children in France. However, further reducing exposure is a public health goal because there is no clear toxicological threshold. The identification of the environmental determinants of BLLs as well as risk factors associated with high BLLs is important to update prevention strategies. We aimed to estimate the contribution of environmental sources of lead to different BLLs in children in France. We enrolled 484 children aged from 6months to 6years, in a nationwide cross-sectional survey in 2008-2009. We measured lead concentrations in blood and environmental samples (water, soils, household settled dusts, paints, cosmetics and traditional cookware). We performed two models: a multivariate generalized additive model on the geometric mean (GM), and a quantile regression model on the 10th, 25th, 50th, 75th and 90th quantile of BLLs. The GM of BLLs was 13.8µg/L (=1.38µg/dL) (95% confidence intervals (CI): 12.7-14.9) and the 90th quantile was 25.7µg/L (CI: 24.2-29.5). Household and common area dust, tap water, interior paint, ceramic cookware, traditional cosmetics, playground soil and dust, and environmental tobacco smoke were associated with the GM of BLLs. Household dust and tap water made the largest contributions to both the GM and the 90th quantile of BLLs. The concentration of lead in dust was positively correlated with all quantiles of BLLs even at low concentrations. Lead concentrations in tap water above 5µg/L were also positively correlated with the GM, 75th and 90th quantiles of BLLs in children drinking tap water. Preventative actions must target household settled dust and tap water to reduce the BLLs of children in France. The use of traditional cosmetics should be avoided whereas ceramic cookware should be limited to decorative purposes.

Blood lead levels and risk factors in young children in France, 2008-2009.

BACKGROUND: The exposure of children to lead has decreased in recent years, thanks notably to the banning of leaded gasoline. However, lead exposure remains a matter of public health concern, because no toxicity threshold has been observed, cognitive effects having been demonstrated even at low levels. It is therefore important to update exposure assessments. A national study was conducted, in 2008-2009, to determine the blood lead level (BLL) distribution in children between the ages of six months and six years in France. We also assessed the contribution of environmental factors. METHODS: This cross-sectional survey included 3831 children recruited at hospitals. Two-stage probability sampling was carried out, with stratification by hospital and French region. Sociodemographic characteristics were recorded, and blood samples and environmental data were collected by questionnaire. Generalized linear model and quantile regression were used to quantify the association between BLL and environmental risk factors. RESULTS: The geometric mean BLL was 14.9µg/l (95% confidence interval (CI)=[14.5-15.4]) and 0.09% of the children (95% CI=[0.03-0.15]) had BLLs exceeding 100µg/l, 1.5% (95% CI=[0.9-2.1] exceeding 50µg/l. Only slight differences were observed between French regions. Environmental factors significantly associated with BLL were the consumption of tap water in homes with lead service connections, peeling paint or recent renovations in old housing, hand-mouth behavior, passive smoking and having a mother born in a country where lead is often used. CONCLUSIONS: In children between the ages of one and six years in France, lead exposure has decreased over the last 15 years as in the US and other European countries. Nevertheless still 76,000 children have BLL over 50µg/l and prevention policies must be pursued, especially keeping in mind there is no known toxicity threshold.

Lead contamination in French children's homes and environment.

Lead in homes is a well-known source of childhood lead exposure, which is still of concern due to the health effects of low lead doses. This study aims to describe lead contamination in the homes of children aged 6 months to 6 years in France (without overseas). Between October 2008 and August 2009, 484 housing units were investigated. Lead in tap water and total and leachable lead levels from floor dust, outdoor soils and paint chips were measured. X-ray fluorescence measurements were carried out on non-metallic and metallic substrates. Nationwide results are provided. The indoor floor dust lead (PbD) geometric mean (GM) was 8.8 µg/m² (0.8 µg/ft²) and 6.8 µg/m² (0.6 µg/ft²) for total and leachable lead respectively; 0.21% of homes had an indoor PbD loading above 430.5 µg/m² (40 µg/ft²). The outdoor play area concentration GM was 33.5 mg/kg and 21.7 mg/kg in total and leachable lead respectively; 1.4% of concentrations were higher than or equal to 400 mg/kg. Outdoor floor PbD GM was 44.4 µg/m² (4.1 µg/ft²) that was approximately 3.2 times higher than the GM of indoor PbD. Lead-based paint (LBP) was present in 25% of dwellings, LBP on only non-metallic substrates was present in 19% of homes and on metallic substrates in 10% of dwellings. The GM of lead concentrations in tap water was below 1 µg/L; 58% of concentrations were lower than 1 µg/L and 2.9% were higher than or equal to 10 µg/L. The age cut-off for homes with lead would be 1974 for paint and 1993 for indoor floor dust. This study provides, for the first time, a look at the state of lead contamination to which children are exposed in French housing. Moreover, it provides policy makers an estimate of the number of French dwellings sheltering children where abatement should be conducted.

The impact of heat islands on mortality in Paris during the August 2003 heat wave.

BACKGROUND: Heat waves have a drastic impact on urban populations, which could increase with climate change. OBJECTIVES: We evaluated new indicators of elderly people's exposure to heat in Paris, from a public health prevention perspective, using satellite thermal images. METHODS: We used a time series of 61 images from the satellites of the National Oceanic and Atmospheric Administration's (NOAA) Advanced Very High Resolution Radiometer (AVHRR) taken from 1 to 13 August 2003 to produce thermal indicators of minimum, maximum, and mean surface temperatures and diurnal temperature amplitude, with different lags between the meteorological data and the health impact. Health data came from a case-control study involving 241 people ≥ 65 years of age who died in the city of Paris or the nearby suburban area of Val-de-Marne during the August 2003 heat wave, and 241 controls who were matched to cases on age, sex, and residential zone. For each person, we integrated the thermal indicators in a conditional logistic regression model, adjusted for age and other potential confounders. We computed odds ratios (ORs) comparing the 90th and 50th percentiles of the temperature differences between cases and controls for various indicators. RESULTS: Mortality risk was significantly associated with exposure for two indicators: minimum temperatures averaged for 1-13 August [for a 0.41°C increase, OR = 2.17; 95% confidence interval (CI): 1.14, 4.16] and minimum temperature averaged on the day of death and the 6 preceding days (for a 0.51°C increase: OR = 2.24; 95% CI: 1.03, 4.87). CONCLUSIONS: Our results support the influence of night temperatures on the health impact of heat waves in urban areas. Urban heat exposure indicators based on satellite imagery have the potential to identify areas with higher risk of death, which could inform intervention decisions by key stakeholders.

Blood lead levels in the adult population living in France the French Nutrition and Health Survey (ENNS 2006-2007).

BACKGROUND: The French Nutrition and Health Survey (ENNS) was conducted in order to describe food consumption and levels of various biomarkers in the general population. In this paper, we aimed to assess the distribution of blood lead levels (BLL) in the adult population living in France. METHOD: ENNS was a cross-sectional survey carried out in the general population. Participants (18-74years of age) were sampled using a three-stage probability design stratified by geographical areas and degrees of urbanization. Collected data included biochemical samples, anthropometric measurements, socio-demographic characteristics, and environmental and occupational exposure. RESULTS: In 2006/2007, 2029 adults were included in the survey on lead. The blood lead geometric mean (GM) in the population living in France was 25.7µg/L [24.9-26.5]. The overall prevalence of elevated BLL (>100µg/L) was 1.7% [1.1-2.3%]. Levels were significantly higher in males than in females, and increased with age, smoking status and alcohol consumption. Other factors significantly associated with BLL were leisure activities, occupational category, age of housing unit, birth place and shellfish/crustacean consumption. CONCLUSION: For the first time a survey provides national estimates of BLL for the adult population in France. Comparison with results from a previous study among men aged 18-28years showed that the GM dropped more than 60% in the last 10years. The distribution of BLL in France was quite similar to that observed in other European countries.

[The practitioner's role in surveillance and information on environmental risks]. / Surveillance et information sur les risques environnementaux: le rôle du praticien.

Health scares have entailed an increasing concern about environmental risks for populations. Authorities' response was to set up a system for the analysis, surveillance and management of environmental risks. Practitioners have an important role to play in this system, as primary actors of surveillance and as a close source of information about the environmental risks for the population. Three examples are developed. Children's lead poisoning still exists and entails irreversible neuropsychic deficits. Its diagnosis rests upon the recognition of risk factors and the prescription of a test of blood lead level. Carbon monoxide poisoning is the first cause of mortality by acute poisoning in France and it causes several thousand hospitalizations every year. Notification of the cases of lead and carbon monoxide poisonings is indispensable to remove their causes. Links between cancer and environment are an important social concern and a public health issue. Practitioners have a key role to play not only in the communication on this subject, but also to notify disturbing sanitary events and participate in the local investigations.