Health and Environment

Populations near Waste-to-Energy plants “do not manifest increased levels of heavy metals”

In 2010, researchers studied concentrations of heavy metals in blood and urine samples from populations both around and away from Bilbao’s Waste-to-Energy plant. These samples were taken in 2006 and 2008 in order to evaluate the eventuality of metal build-up due to the plant.

The researchers found no clear evidence of higher concentration of heavy metals in blood or urine for populations leaving near the plant, and did not find any conclusive evidence of a higher build-up of this concentration over the years compared to populations leaving further from the plant.

This research paper was featured in the European Commission’s “Science for Environment Policy” news service on 11th November 2010.

Full abstract:

In 2005 an urban solid waste incinerator (SWI) was commissioned in Bilbao (Basque Country, Spain). Serum and urine samples were collected from 95 and 107 volunteers in 2006 and 2008 respectively, of which 62 were repeats from the same individuals. Blood lead levels (BPb) were determined, as were the concentrations of cadmium (Cd), chromium (Cr) and mercury (Hg) in urine (UCd, UCr and UHg). The town of Alonsotegi and a borough of Bilbao (Altamira, Rekalde) were considered to be close, less than 2 km from the plant, and correspond to an urban environment with high traffic density. The areas of reference were a borough of Bilbao (Santutxu-Zurbaran), 5 km from the plant, also in an urban area with high traffic density, and a small town with little industrial activity and low traffic density (Balmaseda) 20 km from the plant; neither of these is downwind from the site with respect to prevailing winds. There was a significant correlation for BPb, r=0.63 (p<0.001), between the two surveys. However, there was no linear correlation for the other three metals (UCd, UCr and UHg), between the two sampling periods (p>0.05). Multiple linear regression models did not show increases over time of the levels of BPb, UCd, UCr and UHg in the areas close to the SWI compared to those of areas located further away, after adjusting for confounding variables. These results reinforce the hypothesis that populations near modern plants for solid waste incineration do not manifest increased levels of heavy metals.

Reference: Zubero MB, Aurrekoetxea JJ, Ibarluzea JM, Arenaza MJ, Rodríguez C, Sáenz JR., Heavy metal levels (Pb, Cd, Cr and Hg) in the adult general population near an urban solid waste incinerator.  Science of the Total Environment. (408):4468-4474.