Lead and other heavy metals in soils impacted by exterior legacy paint in residential areas of south west England

摘要

AbstractLegacy paint on publicly-accessible structures in residential areas of Plymouth, UK (a bridge parapet, hospital railings, a goal frame, urban street paving and a telephone kiosk) and local paint-contaminated soils have been analysed for lead and other heavy metals (chromium, zinc and barium) by X-ray fluorescence spectrometry. Lead was detected in all paints analysed (n=56) apart from two fragments of yellow road markings, with maximum concentrations exceeding 300gkg−1. Soils were contaminated by Pb to varying degrees that depended on the condition and Pb content of the paint applications and the nature and vegetation of the soil, with a maximum concentration of 27gkg−1and a maximum enrichment factor normalised to grain size and regional baseline soil of 270. While Cr showed no clear contamination in soils that could be attributed to paint, contamination from this source was evident for Zn in soil by the goal frame and for Ba and Zn in soil by the bridge parapet. Application of a physiologically-based extraction test to the soils revealed stomach bioaccessibilities that were variable among the samples and between the metals but that were greatest for Zn and lowest for Cr. With the exception of Cr, bioaccessibility generally decreased in the intestine, with mean intestinal bioaccessibilities relative to total metal of about 6% for Pb and Ba, 0.9% for Cr and 1.6% for Zn. From both a health and environmental perspective, Pb is the heavy metal of greatest concern because of its common occurrence at high concentrations in legacy paints, coupled with a relatively high bioaccessibility and well-documented chronic neurotoxicity. Public exposure to Pb in residential areas may arise through direct contact with paint or soil or via the intrusion of contaminated geosolids to the household on shoes or as airborne dust.Graphical abstractDisplay OmittedHighlights•Paint fragments from publicly-accessible structures have been analysed by XRF•Lead was observed at concentrations up to about 400 g kg-1•Chromium, zinc and barium were present at percentage concentrations in many cases•Local soils exhibited Pb enrichment factors compared with regional baselines of up to 270•Intestinal bioaccessibility of Pb in soil averaged about 6%•Paint-contaminated soils afford means of direct and indirect Pb exposure in residential areas