Health risks: Scared to Death
July 5, 2011
by Jon Entine
Why everything you thought about the health risks from chemicals is wrong
You're luxuriating in newly constructed digs, napping on your Barcalounger, sipping coffee from a plastic cup, gossiping on your iPhone. Here's today's quiz: What's your biggest health danger?
Based on recent news reports, you'd think you're in cancer alley: formaldehyde leaks from the plasterboard walls, ceiling tiles are made with out-gassing phthalates, radiation spews from your BPA-made phone and the toxic du jour, styrene, leeches into your latte.
Yet as any cancer expert would tell you, that's the wrong answer. By exponential degrees you are far more likely to face serious health danger from sitting on your derrière, which increases obesity and dramatically raises your likelihood of cancer, than from the other well-publicised chemical "threats" combined. This quiz is worth considering, if only to try to put in context two recent news events.
In Germany, some 50 people have died from E coli poisoning and 900 others experienced dangerous reactions from what officials believe were organically grown bean sprouts. E coli contamination of organic foods is not uncommon – recall for example the death and injuries caused by bacteria-spiked Odwalla apple juice in 1996 that led to the largest fine ever assessed by the US Food and Drug Administration and the eventual sale of the company. Yet journalists and activists are not clamouring for tighter controls of the organic industry.
Contrast that silence to the reaction when synthetic chemicals are in the news. In June, the National Toxicology Program (NTP), a US government agency that evaluates the potential hazards of chemicals, listed formaldehyde as a "known human carcinogen" and classified styrene as "reasonably anticipated to be a human carcinogen". What do those classifications mean?
The venerable New York Times headlined a front-page report with Government Says Two Common Materials Pose Risk of Cancer – and that's a restrained example of the risk-drenched headlines that have echoed through cyberspace. Jennifer Sass, the influential anti-chemical campaigner for the Natural Resources Defence Fund (NRDC), did what she could to magnify the cacophony. "The chemical industry fought the truth, the science, and the public – but in the end our government experts came through for us, giving the public accurate information about the health risks from chemicals that are commonly found in our homes, schools, and workplaces."
So, based on the science, Mr and Ms Consumer, should be concerned, right?
Just when you thought it wasn't safe
That's not what the science shows. The average consumer doesn't face health dangers from those substances as we normally encounter them, and the data presented in the NTP report doesn't suggest that they do.
Of the two chemicals, formaldehyde is problematic. The report confirmed the widely known fact that when industrial workers handle it, they face cancer threats – if they are not adequately protected. No study has found serious health dangers from exposure to formaldehyde in, for example, materials used to build your home, although the fumes are known to cause irritation when concentrations are unusually high.
So, what's the responsible, if less than sensational, take-away from the NTP study on formaldehyde? Your house is not making you sick, but tight oversight of production is prudent. In the US, the Occupational Health and Safety Administration sets firm exposure limits to protect workers, and similar regulations are in place in other countries.
The new classification of styrene – a chemical that occurs naturally and synthetically, and is used to manufacture many plastics, latex paints, polyesters and coatings – as a possible carcinogen set off celebrations at the NRDC, where Sass referred to its use in "synthetic flavouring in ice cream and candy".
That's a deliberately misleading reference to the fact that styrene is a natural component of cinnamon as well as beef, coffee beans, peanuts, wheat, oats, strawberries and peaches. The German BfR, known as one of the most conservative risk assessment organisations in the world, studied this very issue in 2006, concluding: "Small amounts of cinnamon have been used for thousands of years as a spice without any reports of side effects… no harmful levels of styrenehave been identified in the cinnamon powder."
The NTP underscored the scientific consensus that studies have not found health dangers in common consumer exposure. And while the NRDC and hundreds of websites blithely claim that "industry pressure" slowed the NTP from listing styrene in its Report on Carcinogens, there is a belief that the NTP went beyond the science in its action.
The World Health Organisation and the International Agency for Research on Cancer (IARC) lists styrene as a "possible human carcinogen", considered by scientists to be a weak warning. That categorisation means something quite different from when a journalist or activist uses the term.
Degrees of risk
For science literates, the translation is that some laboratory studies but not others found that rodents exposed continuously to this chemical at levels 100 to 1,000 times higher than what humans are exposed to developed mutations.
Are consumers in danger as the NRDC claims and the New York Times headline implies? Researchers say no. European Union scientists, who operate under the precautionary principle and are guided by WHO and IARC, recently reviewed the identical studies and concluded that styrene is not a human carcinogen, echoing an expert panel in a report in a November 2009 issue of the Journal of Occupational Environmental Medicine.
Even the data on worker exposure to styrene is questionable. The two most comprehensive studies to date, as noted in the NTP report, showed that workers were no more likely to contract blood cancers than peers working in the absence of styrene.
Misrepresenting science studies and caricaturing corporations as self-interested to the point of being deceptive is a timeworn tradition of "reform minded" consumer advocates. Risk – the danger of being injured – depends on how much of a chemical you're exposed to and for how long. When one looks at the details of many studies, because of sample sizes, controls or other factors, the findings are often suggestive rather than conclusive.
Risk researchers are statistically sophisticated and understand this complexity, but campaigners and the media often do not appreciate the grinding process of science.
For example, BPA has come under relentless attack, yet a slew of recent independent reports disagree – by the FDA in January 2010, the European Food Safety Authority in summer 2010, a 2010 special advisory committee of German toxicologists and the November 2010 meeting of the World Health Organisation expert review panel on BPA. These all concluded that the collective evidence from thousands of studies demonstrates that the small-scale investigative studies touted by interest groups do not lead to the consensus that BPA poses serious danger as an endocrine disruptor.
Even regulators struggle with assessing risk. Recently, the National Academy of Sciences publicly excoriated the US Environmental Protection Agency for its methodology in assessing chemicals under its Integrated Risk Information System (IRIS), the EPA's scientific position on the potential human health effects of exposure to more than 540 chemicals.
The NAS concluded that the EPA's "criteria to identify evidence for selecting and evaluating studies" were often flawed and misguided, conclusions overstated and reports not presented in a logically consistent manner – and must include a more balanced "weight of evidence" review.
Rush to the unknown
The costs to society – economically and socially – from setting policies based on fear rather than science are significant. It often leads to political pressure to slap warning labels on packages that amount to a skull-and-cross-bones, stirring unnecessary concerns among consumers and workers. Companies come under siege and jobs are threatened. Scared or confused, consumers switch to products made with ingredients that have been tested far less, in effect rolling the toxic dice.
This script played out in France in June. An intense campaign targeting phthalates led some legislators in the French parliament to pass a wholesale ban, rejecting recommendations of the French health minister. But while French politicians capitulated to fear, the Danish Environmental Protection Agency, one of the most aggressive regulatory bodies in the world, took a measured and nuanced approach, distinguishing between the potential risks presented by different types of phthalates.
It has proposed a ban on low molecular weight phthalates widely used in children's toys and some medical tubing – DEHP, BBP, DBP and DIBP – which may accumulate in the body and where the evidence of potential danger is stronger.
Frank Jensen, chief adviser to the Danish EPA's chemical unit, noted that high molecular weight plasticisers such as DINP, DIDP and DPHP are more stable and resilient and make cost effective, quality substitutes for the low ones. EU officials agree with this distinction, but French politicians took a less sophisticated approach.
The fear of synthetic chemicals diverts our focus and drains public funds from addressing documented dangers. That's underscored by a just-released American Cancer Society report. Despite the hysteria suggesting that modern society is being assaulted by its increased reliance on synthetics, chemical exposure represents "relatively small risks" and human cancer rates continue their steady decline.
Cancer caused by chemicals is mostly confined to work settings, amounting to about 4%, with pollution and all other exposures adding another 2% of cases. The increasing danger is from obesity and lack of exercise. That contributes to an estimated one out of five cancer-related deaths.
Exaggerating risk is not prudent; it's irresponsible. We don't demand bans on coffee,which contains more than 1,000 chemicals, including 19 known rodent carcinogens, even though high amounts of caffeine have been implicated in increased risk of bladder and oesophageal cancer. We need a science-based approach to chemical regulation.It is safe to relax on the lounger in your new house, talk on your phone and drink your cup of Joe.
Jon Entine is director of the Genetic Literacy Project at Stats at George Mason University, and founder of the sustainability consultancy ESG MediaMetrics. He is author of Scared to Death: How Chemophobia Threatens Public Health.
Copyright © 19992011 Jon Entineall rights reserved