You may think that what's outside won't harm you inside your home, but if your kids play in the yard they can be exposed to various chemicals — including fertilizers, pesticides, and lead in the soil — that they end up trekking indoors. Recommended yard products include those by NaturaLawn of America (nl-amer.com).

  1. Know your green

    “Don't rely on the word green when you're looking for lawn-care products,” says Sass. “You have no idea what's really in the products.” The easiest way to decipher the level of toxicity, says Sass, is to read the ingredients: If you see a lot of chemicals with long, complicated names that you would need a PhD to understand, be wary of the product. Instead, look for those that contain recognizable ingredients.

  2. Don't go bare

    Anything from nearby bridge construction (which often involves lead) to lead-based exterior paint can release this unhealthy metal into the soil, where it accumulates, says Marstiller. “If your kids play in the soil, they can get exposed.” She recommends covering any bare soil with grass, mulch, or gravel, which create a barrier, keeping contact to a minimum while playing or working outside.