Carbon Dioxide is toxic to humans and animals. If left unchecked in enclosures, homes, and buildings, it could be fatal and can cause death. Studies are now being implemented how to compute the levels of CO2 in homes and buildings with respect to its occupants.
The Texas Border, which houses 1.3 million people, are vulnerable to Zika virus because most of their houses don't have sufficient air-conditioning and window screens to protect them from mosquitoes. Mosquitoes are known to carry the virus.
The rise of levels of mercury found in women of child bearing age is a fact that the neurotoxic element is creeping in systems of humanity. Mercury is found in the food we eat, gold and coal mining. Coal used as fuel emits toxic mercury when combusted.