In Mortagne-du-Nord, in the Nord department, there was once a zinc smelter, a sulfuric acid plant, and a lead smelter. Although the last of these plants has been closed since 1968, heavy metal contamination of the soil and sediments is still present on and around the site. The high concentrations of lead, zinc, and cadmium at the site have raised the question of whether studies are needed to assess the population’s exposure to these elements. The objective is to issue an opinion on the relevance of screening for lead poisoning and measuring the population’s exposure to cadmium. For cadmium, the estimated exposure per person reaches a maximum of 33.4 μg/day. This remains well below the toxicological reference value of 60 μg/day. Exposure is therefore acceptable. Measuring cadmium exposure in the population is not relevant. For children living in the central contamination zone, the distribution of blood lead levels indicates that levels exceeding 100 μg/L are possible. The probability of exceeding 100 μg/L ranges from 0.8% to 6.3% depending on the presumed bioavailability of lead. This probability is likely still overestimated. Overall, it does not appear relevant to organize systematic screening for blood lead levels, as its effectiveness would be very limited. The presence of older housing and post-industrial exposure justifies informing and raising awareness among general practitioners and pediatricians in the area about these specific risk factors for lead poisoning, so that they can assess, for each child aged 0 to 6 and pregnant women in their patient population, the appropriateness of prescribing individual screening. This recommendation aligns with the "Practical Guide to Lead Poisoning in Children and Pregnant Women," which advises screening for risk factors during medical visits. The public must also be informed of the potential risk of lead poisoning for children and pregnant women. In particular, they should be informed of the risk of significant contamination in gardens, as has been demonstrated in certain cases. (R.A.)