Abstract

The soil in many inner cities and urban areas contains diffuse lead contamination. This means that there is no clear source of the contamination. The lead concentrations in such areas also differ greatly, and a large area is contaminated. This is particularly the case in neighbourhoods in areas that were city centres before the war, old village centres, and fen areas where the ground level was raised and solidified.

Because it is expensive and drastic to clean all the soil in these areas, policymakers rely partly on user advice when tackling diffuse lead, which should reduce exposure. Examples include washing hands after gardening and washing children's hands after playing outside and growing vegetables in containers filled with clean soil. Due to behaviour adopted by people themselves, such as washing home-grown vegetables and laying tiles in gardens, the exposure is reduced but that is not sufficient.

It was not yet known whether residents follow usage advice and indeed reduce exposure. Knowledge about this is important, because lead in the soil can quickly pose risks to the health of people, especially children. Even with low exposures. In Zaanstad, RIVM has investigated whether residents receive user advice and as a result take additional measures. As it turns out, the latter happens much less frequently than is generally assumed to be the case, in spite of a large-scale communication campaign.

These results may indicate a need for extra measures, such as restrictions in use and cleaning the soil more often. In order to ascertain whether this is so, RIVM recommends that the study be repeated in other municipalities.