50 percent to 80 percent harmful to the environment and human health http://www.prb.org/Publications/Articles/2013/e-waste.aspx 80 percent 80 percent land and water-based ecosystems http://www.prb.org/Publications/Articles/2013/e-waste.aspx www.prb.org/Publications/Articles/2013/e-waste.aspx http://www.prb.org/Publications/Articles/2013/e-waste.aspx environmental risks from e-waste Researchers The human and environmental effects of e-waste PRB http://www.prb.org/Publications/Articles/2013/e-waste.aspx