From lead-lined, cathode ray tubes from old TVs, to lead and chromium in circuit boards, e-waste can contain substances that are hazardous to human health if not dealt with properly, including mercury, cadmium and lead. E-waste can pollute water sources and food supply chains. This is particularly true of older products making up today’s e-waste. Regulation and some voluntary targets are driving the phase out of some of the worst offenders in new products.