Along with spring comes pesticide use, especially herbicides for lawns and along roadsides. Note that in a new study of children with brain cancer, twice as many children who had been exposed to pesticides in the two years prior to their birth developed the disease. Children of fathers who washed immediately following applying herbicides to their lawns had lower rates. Childhood leukemia has also been linked to herbicides and pesticide use, prompting a ban on cosmetic pesticides in some Canadian provinces. (You can read about the Canadian governments struggle with Dow Chemical Company as a result, here. )
Consider alternatives to pesticides. One source of easy-to-use factsheets about least toxic control of pests in the home and garden for specific pest and weed challenges is Beyond Pesticides, a not-for-profit organization.