"The Salt" article claims that only "a small group of activists has claimed that biosolids are toxic and full of heavy metals, pharmaceuticals and other chemicals." This cuts straight to the heart of the industry and government's justification for ignoring harm from this North American wide practice. When sewage spreading started on Ottawa Canada farmland back in the 1990s, we rural people living near the spreading areas investigated and raised concerns about contamination of the aquifer we draw our well water from. Ottawa's medical officer of health responded "even if all your wells are contaminated by sewage spreading, and you all get sick from it, that wouldn't constitute an epidemic because people with wells are less than 5% of Ottawa's population". We since learned that this is known as "risk management". Whenever the numbers at risk of direct harm of illness from an industrial practice are less than 5% of the municipal population, there is no official requirement or justification to spend money investigating or doing research to protect such a statistically insignificant group of people. This from doctors who took the Hippocratic Oath to "do no harm"!
If the author was really interested in land application of sewage sludge and any studies on adverse health impacts from exposure, perhaps she should have done a "Google" search for National Institute of Health's site for "sewage sludge research." She would have found 91,900 scientific articles. If she had done a further search on the NIH site for "sewage sludge adverse health impacts," she would have gotten 800,000 research articles on that subject--(does that sound like a small group of activists?). Perhaps she needs to do a little more research before her next article and posts opinions expressed from the "industry friendly bought and paid for" researchers (I will not call Sally Brown a scientists because she violated the foundation of independent investigation to reach a verifiable, sound conclusion--without bias and without payment for hire!) NPR and SALT blog should retract this article as tainted!
As a long time supporter of NPR, it is always disconcerting when they do biased articles. I've found this true in other environmental cases. Even when pressed to rewrite, they still wind up with the same bias! This bad piece of journalism goes to show that the author did not do research beyond interviews, and that it is an industry piece. When Cornell, USGS, EPA, Switzerland, farmers in France and the world over that have experienced degraded soils, loss of livestock and bees, home sites and health, are joined by numerous food companies that refuse to accept food grown in sludge, one must applaud Whole Foods for taking the stand it has. If the writer and those pro the land spreading of toxic waste water treatment plant sludge purchase certain products not grown in this waste and shop at Whole Foods, they have those of us around the world that fight to end this toxic practice to thank for the protection of their health and that of the health of their families.
The "just traces" argument is misleading on so many levels. Current sludge regulations have standards for only a handful of metals and nitrogen. And even these standards are much more lenient than those of other industrialized countries that land apply sludges. For example, no amount of lead-not even trace amounts-should be deliberately applied to garden soil or where children play. Yet EPA/USDA claim that 400 parts per million of lead in soil where children play is safe. Urban sludges contain a lot more than just toxic metals. It is an unpredictable complex mixture of thousands of industrial chemical compounds as well as harmful biological agents. Toxicologists are finding that the principle " the dose makes the poison" may be too simplistic when measuring the health and environmental risks of complex mixtures. The principle does not address synergistic effects, interactions, and the toxicity of breakdown products. The 2002 National Academy of Sciences biosolids report recognized this problem and warned that chemical-by-chemical risk assessment will not gauge the true risks of land application because the degree of complexity and uncertainty "requires some form of active health and environmental tracking."
"Traditional toxicology assumes that there is a direct linear relationship between dose and effect. Not so for endocrine disrupting chemicals (EDCs)." Sewage sludge is full of EDCs. "Low doses--trace amounts-- of EDCs work in ways that are totally unpredicted by traditional toxicology," according to an internationally renowned EDC expert." For every EDC we test, there will be a non-monotonic response. See
http://www.nature.com/news/toxicology-the-learning-curve-1.11644?WT.ec_id=NEWS-20121030
In other words, EDC's can harm organisms in parts per trillion-- depending on the time of exposure. Other unregulated chemicals such as dioxins and PCBs, ubiquitous in land applied sewage sludge, also harm organisms in part per trillion. But they magnify in the food chain, and concentrate, for example, in milk from cows that graze on sludge-treated pastures.
"But in fact, the U.S. Environmental Protection Agency (EPA) found in 2009 that dozens of hazardous materials, not regulated and not required to be tested for, have been documented in each and every one of the sludge samples the agency took from locations around the country. "
This article doesn't mention the quantities they found. Assay techniques are pretty sensitive these days. Did they find enough to be worried about, or just traces?
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