(Beyond Pesticides, September 30, 2009) The Center the Food Safety and the Resource Institute for Low Entropy Systems have petitioned the City of San Francisco and the San Francisco Public Utilities Commission (SFPUC) to immediately suspend the SFPUC’s Compost Giveaway program because the compost is made with sewage sludge which contains toxic chemicals and hazardous materials.
The petition, submitted last Wednesday, cites that the distribution of contaminated compost will spread toxic sludge to homeowners’ backyards, increasing the risk of health problems to children and the community. The SFPUC’s compost giveaway program distributes free compost as part of the commission’s recycling efforts to community gardens, school gardens and local residents. The compost is made of sewage sludge, derived as a by-product of wastewater and sewage treatment, and contains heavy metals, pathogens, pharmaceuticals, PCB’s, flame retardants and endocrine disruptors, such as the antibacterial triclosan.
“San Franciscans may think they’re getting a gift from the city, but this is no gift. City residents could be at serious risk of poisoning from the application of sewage sludge to local crops and gardens,” said Paige Tomaselli, staff attorney for the Center for Food Safety. “With this petition, we’re strongly urging the Mayor to put an immediate end to the toxic giveaways, which carry the risk of dangerous and far-reaching impacts on the health of our most vulnerable citizens.”
Studies show that sewage sludge can pose severe threats to human health, especially for children who are more developmentally vulnerable to toxic chemicals than adults. The SFPUC claims that sewage sludge treated with heat, anaerobic digestion, and then composted is “non-hazardous and nontoxic” and can be “safely used for growing edible vegetables and fruits.” However, no toxic analysis has actually been conducted by SFPUC.
A recent Sewage Sludge Survey from the U.S. Environmental Protection Agency (EPA) identified high concentrations of toxic contaminants like heavy metals, steroids and pharmaceuticals, including the antibacterials, triclocarban and triclosan, in sewage sludge from across the country. EPA finds that nearly all sewage sludge samples collected contain 27 metals, 10 different flame retardants, 12 pharmaceuticals, and high levels of known endocrine disruptors. This data confirms a host of independent scientific research which finds that widely used chemicals are finding their way into the environment, contaminating surface and drinking waters, as well as potentially impacting human and environmental health. This EPA report also correlates with U.S. Geological Survey (USGS) studies that have found that the antimicrobial chemical triclosan is among the most detected in U.S. surface waters.
Serious health problems have been directly linked to the land application of sewage sludge. Toxiic chemicals found in sewage sludge become food safety hazards when the compost is used on gardens, farms, or rangelands. Organic pollutants, such as polycyclic aromatic hydrocarbons, PCBs, DDT degradation products, chlordane, synthetic musk products and tributytin, all known to have serious health impacts, have been found to be present in U.S. sludge. Compost made from lawn clippings, straw, leaves and other vegetation treated with herbicides have been responsible for many incidences of contamination of organic and greenhouse crops. School gardens using contaminated compost where children will be involved in planting, growing and eating food grown with the compost are of the most concern since children are very vulnerable to chemical exposures due to their still developing young bodies.
Composting is still a great way to improve the health of soil by adding much-needed organic content to soil. However, it is best to utilize organic compost, free of synthetic chemicals and avoid compost consisting of sewage sludge and other synthetic chemicals. Luckily, compost is relatively easy to make at home. For more information on organic compost, read our factsheet, “Compost Is the Key to Successful Plant Management”
Source: Center for Food Safety