Weegy: There are no practical alternatives for them other than not to use them. For example, the lead-acid battery, despite all the nasty things said about it, is still a common battery in most cars. [ With lead costing about 20 cents a pound, a replacement with some unusal, expensive relatively rare element will hit you in the pockebook. Are you willing to take the hit? http:// /question/?qid=20071206224344AAjJRQ1 ]
User: whay is heavy metals? why are they such an environmental problem?
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