Lead is a heavy metal that is toxic at very low exposure levels and has acute and chronic effects on human health. It is a multi-organ system toxicant that can cause neurological, cardiovascular, renal, gastrointestinal, haematological and reproductive effects. It is released by various natural and anthropogenic sources into the atmosphere and into aquatic and terrestrial environments. Lead can move in the environment between water, air and soil, which may change the pattern of exposure. Lead is used and traded globally as a metal in various products e.g. batteries, different compounds, lead sheets, ammunition, alloys, cable sheathing and petrol additives.
Cadmium is a non-essential and toxic element for humans mainly affecting kidneys and the skeleton. It is also a carcinogen by inhalation. Cadmium is accumulated in bone and may serve as a source of exposure later in life. Cadmium is used as a pigment, a stabilizer for plastics and as a component of batteries. Cadmium is also widely distributed when it is present as a contaminant in fertilizers.
In the environment, Lead and Cadmium are toxic to plants, animals and micro-organisms. Lead and Cadmium are metals that are mainly transported over local, national or regional distances. The export of new and used products containing lead and cadmium, remains a challenge for developing countries and countries with economies in transition which lack the capacity to manage and dispose of the substances in products in an environmentally sound manner.
Since 2001, UNEP has been mandated to address Lead and Cadmium issues.