High precision blood lead radiogenic isotope signatures in a community exposed to Pb contaminated soils and implications for the current Pb exposure of the European population.

Our study provides the most comprehensive dataset for high-precision radiogenic isotopes of lead (Pb) in blood for the western European population. It investigates their potential for elucidating the contribution of soil Pb to blood Pb using a human biomonitoring survey involving 81 adults and 4 children living in the urban area of Liège (Belgium). Soils in the area show moderate (median of 360 mg/kg) to high (95th percentile of 1000 mg/kg) Pb concentrations, due to former metal processing activities. Blood lead levels (BLL) measured in the study population are, on average, quantitatively consistent with a âˆ¼ 20 % increase due to the exposure to Pb from soils, as estimated by a single-compartment biokinetic model. Consistently, its isotopic composition does not represent an endmember that fully accounts for the variability of Blood lead isotope (BLI) compositions measured in the study population. While some individuals show more thorogenic BLI ratios (relatively more enriched in 208Pb), which could be consistent with a greater exposure to local soils and/or by their country of birth, the BLI data mostly follow a trend roughly parallel to the European Standard Lead Pollution (ESLP) line, within the European leaded gasoline field, even two decades after the withdrawal of this source. Differences in BLI are probably associated with factors related to the presence of Pb in dwellings (pipes, paint) and drinking water distribution system, suggesting that the anthropogenic Pb in use, relevant to human exposure, may contain ore components of different origins, including the Australian Pb ore signature.

Human biomonitoring survey (Pb, Cd, As, Cu, Zn, Mo) for urban gardeners exposed to metal contaminated soils.

Eighty eight adult gardeners and their relatives volunteered to provide urine and blood samples for a human biomonitoring survey among users of one of the biggest allotment garden from Wallonia, showing high trace metal(oid) concentrations in soils. The purpose was to determine if environmental levels of lead (Pb), cadmium (Cd) and arsenic (As) led to concentrations of potential health concern in the study population. Blood and urine biomarkers were compared to reference and intervention cut-off values selected from the literature. The study population exhibited (i) moderately high blood lead levels with median value of 23.1 µg/L, (ii) high urinary concentrations of speciated As (inorganic arsenic and its metabolites) with a median value of 7.17 µg/g.cr., i.e. twice the median values usually observed in general populations, and (iii) very high Cd levels in urine with a median value of 1.23 µg/L, in the range of 95th-97.5th percentiles measured in general adult populations. Biomarker levels in the study population were also mostly above those measured in adults from local populations living on contaminated soils, as reported in the current literature. All biomarkers of Pb, Cd and As showed weak to strong statistically significant correlations, pointing towards a joint environmental source to these three contaminants as being at least partially responsible for the high exposure levels observed. Urine and blood biomarkers show statistically significant associations with variables related to individual characteristics (age, smoking status, …) and Pb domestic sources (Pb pipes, cosmetics, …) but involves also behavioral and consuming habits related to gardening activities on the contaminated allotment garden. At such levels, owing to co-exposure and additive effects of Cd, As and Pb regarding renal toxicity known from literature, the study strongly suggests that this population of gardeners is at risk with respect to chronic kidney diseases.

Sustainable health-based soil standards for arsenic using epidemiological data and toxicokinetic/probabilistic modelling.

This study presents an alternative method to the traditional reference dose approach for the determination of health risk-based soil standards for arsenic. The model combines multimedia equations for air, soil and dietary exposure, a toxicokinetic component, a probabilistic output, a reference distribution for urine arsenic in the general population and exposure parameters values traceable in US-EPA or EFSA reference studies. The model calculates a mean inorganic As urine concentration AsU (sum of inorganic arsenic Asi and its metabolites) from environmental data and exposure parameters, which is attributed to the central value of a lognormal distribution. Risk is assessed by comparing a high percentile of the modelled distribution to the target AsU attributed to the reference value of 10 µg/gCREA (microgram As per gram of creatinine), the upper confidence interval of the 95th percentile from the AsU distribution in the French population. A soil standard value of 40 mg/kg is determined as being the arsenic concentration in soil not giving rise to more than 5% probability of having a AsU concentration above the target value of 10 µg/gCREA. Once soil As concentrations above 40 mg/kg are measured, further environmental investigations should be carried, involving an assessment of As bioaccessibility to address health risks and decide of regulatory measures in residential setting.

Inputs, dynamics and potential impacts of silver (Ag) from urban wastewater to a highly turbid estuary (SW France).

Although silver (Ag) has been listed as a priority pollutant for the aquatic environment by the European Union (Directive 2006/11/EC), the use of Ag-based products with antimicrobial effects is increasing in Europe, as well as North America and Asia. This study investigates personal care products (PCP) as a potential source of Ag in wastewater, as well as the dynamics and fate of Ag in the influent and effluent of a major urban wastewater treatment plant (WWTP) located on the fluvial part of the Gironde Estuary. Typical household PCPs marked as using Ag contained concentrations of up to 0.4 mg kg-1 making them likely contributors to urban Ag released into the aquatic environment. Silver concentrations in influent wastewater generally occurred during mid-week working hours and decreased during the night and on weekends clearly indicating the dominance of urban sources. Up to 90% of the total Ag in wastewater was bound to particles and efficiently (>80%) removed by the treatment process, whereas 20% of Ag was released into the fluvial estuary. Silver concentrations in wastewater effluents clearly exceeded estuarine concentrations and may strongly amplify the local Ag concentrations and fluxes, especially during summer rainstorms in low river discharge conditions. Further work should focus on environmental effects and fate of urban Ag release due to immediate localized outfall and/or the adsorption on estuarine particles and subsequent release as dissolved Ag chloro-complexes within the estuarine salinity gradient.