You may want to think twice before biting into that home grown tomato! Sure homegrown produce tastes better, but using public compost could expose your veggies—and you—to damaging levels of lead. Here’s why: Many municipalities pick up lawn clippings and organic debris for composting to later be shared with the community. Unfortunately, as they recently found out in Boston, if the materials coming from homes are tainted with lead or other contaminants, consequently so is the compost.

Environmental officials recommend that compost containing lead concentrations of more than 150 parts per million not be used in gardens. Last year, Boston’s mean concentration of lead in compost was 299 parts per million, with a high of 480 parts per million (far exceeding limits). As a result of severely elevated concentrations of lead, thousands of tons of compost were ruled to be off limits to Boston residents who were hoping to take advantage of the free fertilizer. This lead-riddled compost, predominantly used to grow fruits and vegetables, is extremely hazardous to your health as the contaminants from the soil spread to the produce you later consume.

But Boston isn’t the only city with older homes, which typically have old lead paint. In the New York Tri-State area, more than 80% of homes were built prior to 1978, the year that lead paint was banned. If not properly cared for, simply opening a door or window in one of these homes could spread of toxic lead dust, not only in the house, but throughout the yard and neighborhood as well.

If you live in a home built pre-1978 or in an area with older homes, be sure to have your home and soil tested – especially if you plan to share your lawn clippings with your municipality for composting. Lead poisoning is preventable – be sure you do your part!