Soil sampling in Houston's greater Fifth Ward reveals toxic levels of lead in yards, play areas

Houston, like many American cities, has areas with soil contaminated by non-biodegradable and persistent pollutants such as arsenic, lead, nickel and cadmium, known as heavy metals and metalloids. These are both naturally occurring in the atmosphere and a byproduct of industrial metal processing, leaching or runoff and are commonly found in traffic emissions and paint.