Wednesday, August 14, 2013

Understanding risk: A reasonable level of certainty

I love what the EWG is doing. The EWG website has multiple guides for consumer products from makeup to cleaning products. The products are easy to search and clearly rated. Having all of the available data put together in one easy-to-search place is an invaluable aid. The EWG is also doing a good job of getting the message out there that not everything in consumer products is consumer friendly. However, the website does not replace common sense.

Let's review.

The precautionary principle says that if there is a reasonable belief of risk and there is an acceptable alternative, then use the acceptable alternative. This sounds simple, but in practice it can be difficult to interpret and apply to daily life. What is a "reasonable" level of certainty that the risk exists? What level does the risk need to surpass before I believe it is a clear and present danger? How convenient and available must the alternative be before I switch over?

In a previous blog article I talked about zero risk. The main point of the article is that there is no such thing as zero risk. But what is a reasonable level of certainty that the risk exists?

The principle I follow is that if the manufacturing process uses traditional methods and there is little evidence of harm, then the product is okay. Here I mean traditional methods to be those involving physical changes (e.g., freezing, drying, pulverizing into a powder) and well established chemical changes (fermenting, roasting, and so on). If the manufacturing process is relatively new (I'm thinking last 50 years as "new"), then more substantial proof is needed to affirm the safety of the product. If the process is extremely new (let's say last 10-20 years) and involves a radical departure from traditional methods (e.g., genetic changes or extreme chemical changes), then very substantial proof is needed.

For example, there have been very few long term studies on the risks of gmo foods. Because gmos are so new and represent such a large departure from normal practices, I personally feel that more proof is needed to establish the safety of such products. Similarly, I feel that many of the chemicals produced for or as a byproduct of plastics need similar vetting before I can deem them safe.

Here is a counter example. Retinyl acetate is listed on the EWG as an 8 (0 being the best and 10 being the worst for cosmetic products). Retinyl acetate is more commonly known as vitamin A. Clearly, vitamin A has been around for a long time and is vital for normal functions of the body. However, because it is fat soluble too much vitamin A can lead to problems. Lathering your entire body in pure vitamin A every day would quickly lead to high levels of toxicity. Yet it is not clear to me that the level of vitamin A in these products is likely to lead to such high levels of build up. So, knowing that there is vitamin A in a product, by itself, is not enough information to be useful.

Here is another counter example. EWG lists lavender oil as a C (A being best and F being worst for cleaning products). However they present no evidence as to how or why lavender oil is bad (except perhaps that there are no studies on it?). Some of the cleaning products are listed as bad merely because they do not list all of their ingredients. I am in favor of clear and complete labeling, but the absence of complete labeling does not automatically mean that the product is going to cause me harm.

Conclusion: EWG is doing a great job of making valuable information accessible. However that does not replace our need to understand risk -- both its certainty and its level.

Tuesday, August 6, 2013

Organic foods cause food born illness?

The Question

"A friend sent me this...her 'anti-organic' mother-in-law sent it to her. My friend wants to know if there is anything they should do different...she washes her fruits/veggies 3 times. Hmm...I just rinse mine!"

The Answer

This 2002 article from a conservative think tank argues that because organic farmers fertilize their foods with manure, organic produce is leading to an increase in serious food born illnesses. Specifically they point out a virulent strain of E coli -- regular E. coli might give you an upset stomach -- E. coli strain 0157 can lead to hospitalization and, in rare cases, death. They state that in 1996, the CDC reported that there were 250 deaths caused by this strain of E coli.

So, the question is, is this true and what should I do about it?

The short answer: The risk is real, but very small. Most people already practice safe food habits, so there is no need to do anything different.

Safe food habits include buying from a reputable producer (i.e., not a rundown roadside stand), buy only produce that looks fresh (i.e., avoid bruised or moldy produce), and wash your hands with soap and water before preparing and eating food.

The long answer: After reading this article, I did some fact checking. I could not find numbers from 1996, but I figured that since then consumption of organic food has really boomed, so current numbers from the CDC should show even more deaths from food related illnesses. In 2010, the most recent year for which the CDC has verified data, there were only 23 deaths from all food related illnesses combined. If you include hospitalizations, the number goes up to 1,184. (Check for yourself here). That right there makes me think the article was cherry picking the data, but maybe 1996 was a bumper year for food born illness or maybe 2010 was a abnormally quiet year. Let's pretend for argument's sake that 250 deaths per year is the real number for most years. Is this something the average person should worry about?

By itself the number does not really provide a lot of information. If only 250 people ate organic produce and 250 people died, then, yes, I would be terrified! However, this is far from the truth. A Harris poll in 2007 (see the NY Times article here) states that 30% of Americans eat organic produce some of the time. So, if the population of the US is 300 million, then 90 million people eat organic produce at least occasionally. In that case 250/90 million= 0.0003% chance of dying from a food related illness.

Take, by comparison, heart disease. Every year nearly 600,000 people die of heart disease! Atherosclerosis is caused by an unhealthy diet and lack of exercise (as per the Mayo Clinic). If anything, the article should have been written about the dangers of fast food!

Okay, but what about conventional produce? Consider this: "the Environmental Protection Agency estimates that 10,000-20,000 physician-diagnosed pesticide poisonings occur each year among the approximately 2 million U.S. agricultural workers" (as per this CDC article). Let's pretend that absolutely none of the harmful chemicals that sicken these workers actually stays on our food to accumulate in our bodies. Even with that assumption, would you really want to contribute to that? Umm... no, thanks.

What is the real story here? To me, it is the fact that there is no such thing as zero risk. We all live with risk every day of our lives. What we have to do is learn how to evaluate how much the risk affects us and why it scares us. Being hospitalized from a case of really bad food poisoning seems a lot scarier than eating fast food because the results are immediate and understandable. That means it is easier for the human brain to process the message "organic food = food poisoning = bad." By contrast, the relationship between fast food and heart disease is less immediate and clear to us, so we are less likely to behave in a way that benefits us in the long term. I see a similar story play out with environmental problems like climate change all the time.

Being a savvy information consumer is an important skill in today's world. And if you need a second opinion, always ask your personal green expert.

Saturday, August 3, 2013

In the news: Uplifting stories

In the last month, I've read a number of inspiring stories in the news. Here is a quick recap (with links) of what I've learned.

1. In Canada's Globe and Mail, columnist Margaret Wente writes about how a 29-year old entrepreneur, Jon Dwyer, created an alternative fuel that doesn't need government subsidies or specialized technology to work. Flax fuel is cheaper than diesel and runs in diesel motors (without modification). The new form of biodiesel is being used to power Toronto's city fleet and other buildings in the city.

2. In a similar story on NPR, guest host on Morning Edition, John Ydstie, talked about social entrepreneur David Green, who is lowering the price of medical technologies by making cheaper products to compete with conventional ones. This competition drives down prices. Green successfully made a hearing aid with off-the-shelf blue tooth technology at a fraction of the cost of a traditional hearing aid. He's also helped 18 million people see better by making cataract surgery cheaper.

3. Check out the Economist's review of Nature's Fortune, written by Mark Tercek and Jonathan Adams from the Nature Conservancy. The authors describe how putting a price on an ecosystem service allows governments and businesses to incorporate the ecosystem in their planning and thus preserve it. The best known example of this is New York City's decision to restore the Catskill watershed because it was cheaper than building a water purification plant.

4. I wish mainstream news in the US would report more on uplifting human achievements, like BBC did in this article on green heroes. The UK's National Trust was the world's first organization dedicated to conserving natural and historical places (started in 1895!). Each year they celebrate three exceptional volunteers with the Octavia Hill award.Check this out: In 1985 they had three volunteers, now they have over 60,000!