The environmental hazard that I know the most about is lead. A few years ago I had to become a licensed lead abatement supervisor through the IL Dept. of Public Health. In older neighborhoods like mine, it's a very serious problem. Since I'm a former teacher, I've seen a lot of the results, often sitting in special ed classes. We have to have our house tested soon due to the funding we received for converting our house. We've been pretty safe, but we're also going to have the boys tested just to make sure.
I bring this up because it's National Lead Awareness Week. I was reading today that computers that get tossed have become a major source of lead in landfills and can potentially be an issue if people are recycling computers without taking care of the poison.
How do you avoid lead poisoning? There are some very easy steps to take. First, realize that it affects kids under 7 years of age more than anyone else. Make sure your kids are eating a healthy diet and get plenty of calcium, iron, and vitamin C. Lead is a metal, as are calcium and iron. Think about where calcium and iron are found. If your child has lead poisoning, the lead can be found in those locations (bones and teeth, among others). In fact, the first link between lead and behavior disorders was done through the collection of teeth when children lost them. The researcher tested the teeth for lead and then went back and asked the teachers to describe the behavior of all of the children that had given teeth. There was a direct correlation between those who tested for lead and those who were described as unruly.
Anyway, besides a healthy diet, keep the house clean; keep the paint in good condition. Don't let kids eat paint chips, ever. There are lots of other things to do, but these are the easiest ideas for parents to implement. For some more information, you can start
here. Check out the links, as there are tons of them.