There are different kinds of batteries, and they’re made using a variety of materials. What makes batteries dangerous to the environment are the chemicals used to make them.
Apart from mining these resources – which has a detrimental effect on Nature – a battery contains one or more of the following metals: cadmium, lead, zinc, manganese, nickel, silver, mercury, and lithium, as well as acids.
These chemicals are extremely toxic to us and the environment.
Air Pollution: Batteries undergo a photochemical reaction as they decompose in landfills. This causes emissions of greenhouse gases. The greenhouse effect results in global warming / climate change.
Water Pollution: The harmful chemicals found in batteries can also find their way into the local water supply, killing plants and animals which negatively affect the ecosystems of streams, lakes, and rivers. Ultimately, the health of people who drink contaminated water is also at risk. The same can be said when it comes to eating fish found in polluted waters.
Soil Pollution: I already mentioned that most batteries end up in landfills instead of being recycled or disposed of properly. The danger lies in the fact that these batteries contain toxic chemicals that are absorbed by the soil. Once they leak into the surrounding areas, that’s where the deleterious effects take place.