Exposure to lead in outdoor areas
Lead is an element that is toxic to health, especially for young children. As an environmental pollutant, it can contaminate various media including food and airborne dust. In its expert appraisal published today, ANSES concludes that lead-contaminated dust in outdoor public areas (pavements, roads, street furniture, playgrounds, etc.) should be considered as a source of exposure for the general population. The Agency points out that children and certain professionals are the groups most likely to be exposed to this contaminated dust through contact or ingestion. The Agency is therefore issuing recommendations on reducing population exposure to lead on a lasting basis.
The French Ministries of Health and Labour asked ANSES to characterise lead exposure via contaminated dust deposited on the surfaces of outdoor public areas such as pavements, roads, street furniture, outdoor playgrounds, etc. This is because lead can be released into the air from industrial or small-scale work sites and then deposited in the environment. It can also be found in dust due to erosion or leaching from architectural elements containing it, which then contaminates outdoor areas. Lastly, contamination can be caused by accidental pollution, as was the case with the fire at Notre-Dame de Paris in April 2019.
At-risk populations identified
There are few data in the scientific literature on exposure of the general population and workers to lead in dust deposited on outdoor surfaces. The limited data available, including some from French studies, indicate that this environmental contamination can affect blood lead levels.
The populations most at risk of dust contamination are children and certain workers, due to the likelihood of them being in contact with contaminated surfaces. The priority route of exposure seems to be dust ingestion, especially for children who are more likely to put their hands in their mouths.
The Agency therefore concludes that dust deposited on the surfaces of outdoor public areas should be considered as a source of exposure, with a particular focus on places frequented by children.
Assessing exposure associated with the ingestion of contaminated dust
In its expert appraisal, ANSES noted that the various current calculation models and available data are insufficient for a robust assessment of lead exposure via outdoor dust. Therefore, it is not possible to assess the contribution of this source of lead exposure relative to all the others: food, drinking water, indoor dust, air, etc. Nevertheless, ANSES stressed the importance of reducing exposure to outdoor dust without delay.
In its recommendations, the Agency mentions the need to acquire data to model exposure to lead in dust deposited on the surfaces of outdoor public areas.
Reducing exposure to lead from ingestion of outdoor dust
For the general population, the Agency reiterates the preventive measures recommended by the French High Council for Public Health (HCSP) in 2017, such as frequent hand-washing and removing shoes to limit the transport of dust inside homes. For vulnerable populations at increased risk of contamination, especially children, blood lead levels should be measured.
For workers exposed to outdoor dust, in view of the diversity of situations, ANSES recommends beginning by measuring blood lead levels in order to estimate exposure. The Agency also advocates updating the biological values to be used, in accordance with its July 2019 opinion (PDF) (in French). Lastly, the Agency believes that workers performing tasks that may bring them into contact with lead dust deposited on the ground or other contaminated surfaces should receive reinforced individual medical monitoring.
Concerning more specifically the post-fire situation at Notre-Dame de Paris, the results of ANSES's expert appraisal will be used as part of the process initiated under the aegis of the Île-de-France regional health agency, aimed at documenting the usual lead concentrations in outdoor dust in Paris.