Emissions of heavy metals in air

The main heavy metals emitted into the atmosphere by human activities are zinc (Zn), copper (Cu), nickel (Ni), lead (Pb), chromium (Cr), selenium (Se) arsenic (As), mercury (Hg) and cadmium (Cd). These pollutants can be highly toxic and damage the soil, surface waters, forests and crops. Between 1990 and 2007, emissions of heavy metals have declined sharply, particularly for lead (-97%) due to its suppression in gasoline, chromium (-90%), zinc (-86%) and mercury (-70%). Emissions of copper only slightly decreased during the same period (-4.5%) due to increased road and rail traffic at the source of most emissions (catenary wear and brake pads ). Under the Aarhus Protocol on Heavy Metals adopted June 24, 1998, France undertook to limit its emissions of lead, cadmium and mercury in 2000 to a level lower than 1990. These goals were already achieved before the coming into force of this Protocol (December 29, 2003).