Assessment of oral and lung bioaccessibilities of metals from smelter-impacted dust

Soil and dust contamination by metals engenders important environmental and health problems in northern France where a lead smelter was in activity for more than a century. This study aims to look at the long-term effects of... [ view full abstract ]

Soil and dust contamination by metals engenders important environmental and health problems in northern France where a lead smelter was in activity for more than a century. This study aims to look at the long-term effects of the smelter after its closedown on metals accumulation in sidewalk dust for a better assessment of the local population’s exposure to Cd and Pb. The investigation included: (i) the metal distribution in different dust particle sizes, and (ii) the assessment of metal bioaccessibility via ingestion and inhalation of dust.
Fourty sidewalk dusts were collected using a dust-sampling vacuum. The samples were sieved to collect different particle sizes from 0.3 µm to 1 mm. The Unified Bioaccessibility Method was employed to evaluate the oral bioaccessibility of metals in the different particle sizes. Respiratory bioaccessible fraction of Cd and Pb via the finest particles was extracted with lung simulating solution.
Ten years after the smelter closedown, (i) a strong relationship was observed between the concentrations of metals in dust and the distance to the former smelter; (ii) the metal concentrations are high in the finest fraction (0.3-5 µm) and decrease when the particle size increases; (iii) a higher oral bioaccessibility of Cd and Pb was measured in the gastric phase compared to the gastro-intestinal phase; (iv) metal bioaccessibility via inhalation of dust was high (on average 74% and 69%, respectively for Cd and Pb).
The high contamination level of the sidewalk dust studied continues to be a risk for the environment and the population’s health.