|
Humans are not alone in suffering from lead's effects; plants and animals are also affected by lead toxicity to varying degrees depending on species.[50] Animals experience many of the same effects of lead exposure as humans do, such as abdominal pain, peripheral neuropathy, and behavioral changes such as increased aggression.[86] Much of what is known about human lead toxicity and its effects is derived from animal studies.[24] Animals are used to test the effects of treatments, such as chelating agents,[185] and to provide information on the pathophysiology of lead, such as how it is absorbed and distributed in the body.[186] Farm animals such as cows and horses[187] as well as pet animals are also susceptible to the effects of lead toxicity.[143] Sources of lead exposure in pets can be the same as those that present health threats to humans sharing the environment, such as paint and blinds, and there is sometimes lead in toys made for pets.[143] Lead poisoning in a pet dog may indicate that children in the same household are at increased risk for elevated lead levels.[86] Wildlife A large tan bird of prey with dark brown neck feathers and a bare red head sits on a dead cow in a desert with dead grass and scrub Turkey vultures "Cathartes aura" (shown) and California condors can be poisoned when they eat carcasses of animals shot with lead pellets. Lead, one of the leading causes of toxicity in waterfowl, has been known to cause die-offs of wild bird populations.[143] When hunters use lead shot, waterfowl such as ducks can ingest the spent pellets later and be poisoned; predators that eat these birds are also at risk.[188] Lead shot-related waterfowl poisonings were first documented in the US in the 1880s.[86] By 1919, the spent lead pellets from waterfowl hunting was positively identified as the source of waterfowl deaths.[189] Lead shot has been banned for hunting waterfowl in several countries,[86] including the US in 1991 and Canada in 1997.[190] Other threats to wildlife include lead paint, sediment from lead mines and smelters, and lead weights from fishing lines.[190] Lead in some fishing gear has been banned in several countries.[86] The critically endangered California Condor has also been affected by lead poisoning. As scavengers, condors eat carcasses of game that have been shot but not retrieved, and with them the fragments from lead bullets; this increases their lead levels.[191] Among condors around the Grand Canyon, lead poisoning due to eating lead shot is the most frequently diagnosed cause of death.[191] In an effort to protect this species, in areas designated as the California Condor's range the use of projectiles containing lead has been banned to hunt deer, feral pigs, elk, pronghorn antelope, coyotes, ground squirrels, and other non-game wildlife.[192] Also, conservation programs exist which routinely capture condors, check their blood lead levels, and treat cases of poisoning.[191] |
About us|Jobs|Help|Disclaimer|Advertising services|Contact us|Sign in|Website map|Search|
GMT+8, 2015-9-11 20:56 , Processed in 0.131137 second(s), 16 queries .
