Batteries, when disposed of in dumps or landfills, release toxic components which contaminate the soil, watercourses and groundwater, affecting the flora and fauna of the surrounding regions and man by the food chain.
Due to their toxic components, batteries can also affect the quality of the product obtained in the composting of organic waste. Also, burning them in incinerators is not a good practice either, as their toxic residues remain in the ashes and some of them can volatilize, contaminating the atmosphere.
The toxic components found in batteries are: cadmium, lead and mercury.
They all affect the central nervous system, liver, kidneys and lungs as they are bioaccumulative.
Cadmium is carcinogenic, lead can cause anemia, weakness and partial paralysis, and mercury can also cause genetic mutations.
Considering the negative impacts caused to the environment by improper disposal of spent batteries and the need to discipline the disposal and environmentally sound management (collection, reuse, recycling, treatment or disposal) of spent batteries, Resolution No. 257/99 of CONAMA resolves in its first article:
"Batteries which contain in their composition lead, cadmium, mercury and their compounds, necessary for the operation of any type of mobile or fixed appliances, vehicles or systems, as well as electro-electronic products containing them in their structure non-replaceable, after their energy depletion, will be delivered by the users to the merchants that sell them or to the technical assistance network authorized by the respective industries, for transfer to the manufacturers or importers, for them to directly or through third parties adopt the procedures of environmentally sound reuse, recycling, treatment or disposal ".