I’m always attracted to issues in environmental health, not least because ecology was my first academic love. And so two news items caught my eye last week.

The first was a study by researchers at USC that found fine particulate air pollution is much more damaging than previously thought, causing chronic illness like heart disease and diabetes at 4 times the rate previously thought. The California Air Resources Board is set to examine this and similar studies and is likely to tighten standards further on the internal combustion engines that power cars, trucks, and trains which are the principle source of fine particulates.

The second item was a report by the National Research Council recommending that the safety standard for naturally occurring fluoride in water should be half its current level. The so far sacred cow of fluoride added to water by cities was not in question, but the results of the Council’s review should up the ante on that concern. Previously, the standard was 4 parts per million. The Council recommends that a safe dose occurs only below 2 parts per million. That’s not so far from the 1 part per million for city water supplies. The EPA requested the review in order to set new standards.

In both cases, the conclusions were the result of statistical analysis. They looked at how different communities were affected by different levels of exposure. In the case of air pollution, the researchers looked at how many people developed chronic illnesses. For fluoride, they looked at how many people suffered bone fractures and similar conditions.

Here’s an important point: not everyone who was exposed fell ill. At low levels of exposure, only the most susceptible people suffered. With a little more exposure, less susceptible people were affected.

What does “susceptibility” mean? It means your body’s ability to restore the balance that is disrupted by an environmental assault—whether it’s a toxin or a pathogen. Or an allergen.

In an article I wrote recently for the Progressive Health Observer on the increasing prevalence of allergies, I discussed how the increase in asthma and other hypersensitivities is likely due to a degradation of our immune system. I also discuss the environmental factors that might be making it harder for our immune systems to restore balance when assaulted by an allergen.

Are air pollution and fluoride like the allergen? More of it triggers more people? Or are they environmental factors that affect our susceptibility and make it harder for our body’s to restore balance?

When I work with people, that kind of question is always in play: do you maintain and restore health by reducing exposures or by supporting your body’s ability to stay in balance? The right answer, of course, is to do both. How much of each depends on your unique biology and your unique circumstances—also known as your environment.

So when news comes out that a safe level of fine particulate air pollution or naturally occurring fluoride or any other environmental assault has been established, I have to think “Safe for whom?” That a statistical difference can’t be found doesn’t necessarily mean that no one is affected.

The issues in this article are developed (with references) in issue #3 of the Progressive Health Observer in a review article titled “Smog, Deadlier than Ever.”

Related resources are available on the Environmental Health page.