Spatial and temporal analyses of perfluorooctanoic acid in drinking water for external exposure assessment in the Ruhr metropolitan area, Germany

Abstract

Perfluorooctanoic acid (PFOA) and related chemicals among the per- and polyfluoroalkyl substances are widely distributed in the environment. Adverse health effects may occur even at low exposure levels. A large-scale contamination of drinking water resources, especially the rivers Möhne and Ruhr, was detected in North Rhine-Westphalia, Germany, in summer 2006. As a result, concentration data are available from the water supply stations along these rivers and partly from the water network of areas supplied by them. Measurements started after the contamination’s discovery. In addition, there are sparse data from stations in other regions. Further information on the supply structure (river system, station-to-area relations) and expert statements on contamination risks are available. Within the first state-wide environmental-epidemiological study on the general population, these data are temporally and spatially modelled to assign estimated exposure values to the resident population. A generalized linear model with an inverse link offers consistent temporal approaches to model each station’s PFOA data along the river Ruhr and copes with a steeply decreasing temporal data pattern at mainly affected locations. The river’s segments between the main junctions are the most important factor to explain the spatial structure, besides local effects. Deductions from supply stations to areas and, therefore, to the residents’ risk are possible via estimated supply proportions. The resulting potential correlation structure of the supply areas is dominated by the common water supply from the Ruhr. Other areas are often isolated and, therefore, need to be modelled separately. The contamination is homogeneous within most of the areas.

Bivariate Analysis of Birth Weight and Gestational Age Depending on Environmental Exposures: Bayesian Distributional Regression with Copulas

“…Daily estimations are modeled on the spatial level of water supply stations and, afterwards, of so-called water supply areas (Rathjens et al 2020). They are spatio-temporally assigned to the perinatal data by postal code and day of birth, where a postal area's PFOA concentration is averaged from the respective overlapping water supply areas, weighted by population density data from the German national census of 2011 (Statistische Ämter des Bundes und der Länder 2015).…”

“…PFOA is suspected to have adverse health affects with regard to fetal development, among others (Johnson et al 2014;Lam et al 2014). We have analyzed NRW's available PFOA concentration data, measured in drinking water supply stations and networks, in order to assess the residents' external exposure from Summer 2006 on (Rathjens et al 2020). We now spatio-temporally assign these information on local PFOA concentrations in drinking water to our birth data.…”