Over the past decade there has been a steady trickle of studies reporting correlations between exposure to the industrial chemical bisphenol-A (BPA) and various health effects and body functions. There is no doubt that BPA is a hormone mimic, and that it can interfere with our endocrine system. The questions is, 'are the effects significant or can our complex systems deal with small amounts of potentially toxic substances without suffering harm?'

Most BPA is used as a component in polymers such as epoxies and polycarbonate resins. The BPA is locked up in these polymers, and not free to be absorbed by us. It can be released if the polymer is degraded by exposure to harsh conditions but this does not happen under normal use. Most researchers overlook the fact that BPA has been used for many years as a component of the thermally-activated inks that appear on our supermarket and other dockets. From there, it has been shown, it can transfer from the paper and be absorbed through our skin. Wherever we get it from, our exposure to BPA has resulted in us carrying low concentrations of it in our blood. It is excreted in our urine but our continued exposure to it maintains the low level in our bodies. There is a good deal of variation in body burdens, depending on exposure and the bodies' ability to dispose of it.

The present study, by a team of six American authors, reports a correlation between body concentrations of BPA and the statistical likelihood of death from several causes. Correlations are just that: two things observed to happen together, in this case, BPA concentration and likelihood of death. It's tempting to believe that, because two things occur together, the one must be the cause of the other, but observing a correlation is not the same as proving a cause-and-effect relationship.

It might be... but you can't be sure, because it's impossible to rule out that there might be some other cause of the observed effect that's not BPA at all. Of course it's also impossible to do the critical experiments - dosing people under controlled conditions where there are no interfering factors - that might enable us to settle the matter.

Society has reacted in two ways to the correlations that have been reported in recent years. Regulators in a number of countries have examined the evidence and decided that it's not strong enough to cause them to ban the use of BPA in polymers and other products. However, manufacturers of some products have been sensitised to the concerns expressed by some of their customers, and they have ceased the use of BPA-containing products. On a stroll down the 'baby' aisle of a supermarket I spotted 'no BPA' signs on some products, suggesting that polycarbonate plastic had been replaced by some other polymer, perhaps polypropylene that is commonly used in food containers. And more recently I bought a can of tomatoes with a label that proclaimed 'no BPA'. Fruits and vegetable cans have a white polymer inner lining to stop the contents attacking the metal, and some canners have found a BPA-free way to achieve this by using new polymer linings.

The world has been slow to recognise and document the long term public health consequences of bisphenol A (BPA) from a variety of products whose chemistry is novel to human biology, and as an indicator of the escalating burden of fossil fuel-derived polymers like plastic.

However, this family of compounds has been known to have hormonal properties for several decades and are referred to as ‘endocrine disruptors’, usually xeno-estrogens. That they are contributing to the global burden of so-called chronic disease like obesity and diabetes and to cardiovascular disease risk and their sequelae has become evident. So also are adverse effects on reproduction and increased risk of some cancers.

This new population-based study involving the USA National Health and Nutrition Survey for 2003-2008 linked to mortality until 2015 makes it clear, if not surprising, that this exposure is reducing survival. And bear in mind that the burden of global contamination and pollution with these compounds, along with microplastic and nanoplastic on land and in water, especially the oceans, is continuing and has roughly doubled in 10 years. There is now virtually no form of sea life which is free of endocrine disruptors, with the particles binding about five times the amount because of their peculiar binding sites.

Until the late 1950s, compounds like these plastic polymers and their waste were scarcely known. There were no studies of their human health risk when introduced as we would expect today, yet they have changed our ecology forever. This waste now riddles the world, its food supply, its water, its atmosphere in aerosolic form, our textiles, cosmetics, household furnishings, toys, and more and are inescapable.

By 2003-2004, the corresponding National Health and Nutrition Examination Survey to the present report revealed that 93 per cent of Americans had detectable levels of BPA in their urine. They are, and will, affect our health in some ways we know and in others yet to unfold. The adverse effect on laboratory animal immunity is now being seen.

This, of course, is happening at a time when our innate immunity is crucial in our resistance to viral pandemics. Worse, their biological effects are intergenerational, so that parental exposure affects descendant health. It is now a matter of urgency that we reduce our dependency on plastic polymers and the burden of waste it creates. It is another price we pay for the use of fossil fuels, not just for energy, but for ‘things'. The fossil fuel industrial complex is taking us to the eco-health tipping point!