The American Council on Science and Health published a report on Thursday that looked at which metals are among the safest, and which have the highest levels of exposure.
The group said that of the 50 most common metals, 18 are found in water and 7 in the atmosphere.
The report also looked at the most common types of metals, which it said are mainly found in rocks and soil, metals found in metals and other materials, and metals used for building.
Among the metals studied were arsenic, chromium, copper, nickel, and lead.
The metals were also ranked on how they affect human health, which the A.C.S.H. called “one of the most complex and sensitive environmental issues to address.”
It said lead is a “very toxic” metal.
Lead has been linked to brain damage, and the U.S., Canada, and Europe are now banning the metal in gasoline.
Other metals in the list included aluminum, nickel and iron, which all have been linked with cancer and other neurological problems.
The most dangerous metals in our water are arsenic, copper and cadmium, which are known to be extremely toxic to humans and wildlife.
The A. C.
S and its members are concerned about lead and cadmetium in drinking water, but they are less concerned about mercury, which is found in a small number of metals.
They say that mercury is a known carcinogen.
Lead is not the only toxic metal that has been found in drinking-water.
The U. S. Environmental Protection Agency has also found lead in some drinking water supplies in Pennsylvania and Washington state, and in several other states.
The chemical also can leach from pipes and into drinking water systems.
The government’s Environmental Protection Authority has said that there are no health risks associated with lead exposure.