narrator: while howard hu is studying the health effects mining can have on a community dr. robin whyatt of the columbia center for children's environmental health is concerned with a more widespread environmental problem -- exposure to pesticides. woman: pesticides are designed to be toxic. they're designed to kill. and a lot of them can kill humans through the same mechanisms that they kill insects. it's just that the dose has to be lots, lots higher. so what you want to be sure, then is that that dose is below ones that would be causing any problems in humans. narrator: the location of whyatt's study may seem unusual -- new york's inner city. dr. whyatt: people do think of pesticides as agricultural only, but that's just not at all accurate. about 10% of pesticide use in the united states is used in and around the home. and there was a study done in 1997 that showed that more gallons of specific types of pesticides were used in manhattan than any other place in new york state, including in the agricultural communities. my main area of research is to look to see whether or