Study of contamination of the atmosphere by injurious road transport and industrial products.
D000397:Air Pollution; D002031:Bulgaria; D002248:Carbon Monoxide / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007220:Industrial Waste; D007854:Lead / Q000032:analysis*; D010507:Periodicity; D011166:Porphyrins / Q000652:urine*; D001335:Vehicle Emissions
D007220:Industrial Waste; D011166:Porphyrins; D001335:Vehicle Emissions; D007854:Lead; D002248:Carbon Monoxide