External and Internal Drivers of Unhealthy Ageing

Lead and cadmium are ubiquitous environmental toxicants, which at high exposure levels cause hypertension and renal failure. In the 1980s, Belgium was worldwide the second largest cadmium producer, using a pyrolytic refinement of zinc ore, whereby half of the production escaped into the environment. In the United States, lead-containing paint was only effectively banned in 1976 and leaded gasoline was completely phased out only in 1995. As demonstrated by Flemish Study on Environment, Genes and Health Outcomes (FLEMENGHO) and the National Health Examination Survey (NHANES) in the United States, exposure levels drastically fell. This change in exposure levels needs a revision of the health effects associated with much lower exposure levels than published before. The doctoral proposal builds on Study for Promotion of Health in Recycling Lead (SPHERL; NCT02243904), Flemish Study on Environment, Genes and Health Outcomes (FLEMENGHO; S58273), National Health, Nutrition Examination Survey (NHANES IV) and Environmental influence on early ageing (ENVIRONAGE). This doctoral project will investigate the health effects of environmental (FLEMENGHO and NHANES IV) and occupational (SPHERL) exposure to heavy metals. Both the environmental and occupational exposure levels of lead and cadmium, drastically declined over past decades, so that the dose-response and dose-effect curves need to be revised in the light of the current exposure of populations and workers. Further research based on FLEMENGHO will address the association of lead- and cadmium-associated health effects in relation to the urinary proteomic signature, which will allow moving into new grounds in understanding the molecular mechanisms underlying low-level toxicity. The NHANES IV data will be used to verify the population health metrics associated with exposure to lead and cadmium, thereby bringing estimates of mortality attributable to these toxic metals. Based on ENVIRONAGE data, the candidate will also explore the health impacts in the children cohorts of environmental lead exposure at current-day levels.