I don’t think Einstein had chemical anxiety or the amount of chemicals in our urine in mind when he famously stated that “not everything that counts can be measured and not everything that can be measured counts.” But I think the quote has great relevance when it comes to current chemical concerns. Scarcely a day goes by without some activist organization clamoring about the number of “untested” chemicals to which we are exposed, and lamenting the “fact” that we have become a nation of “unwitting guinea pigs.” True, we are exposed to chemicals, hundreds of thousands every day. Sniff that cup of coffee and you’ve just exposed yourself to over a thousand compounds! Of course, like the vast majority of chemicals to which we are exposed, these are natural. But that is neither here nor there. Toxicity is not determined by a chemical’s ancestry. It is determined by appropriate studies.
Chemicals that enter the body eventually emerge in one form or another. Eat a bowl of chicken soup and hundreds of chemicals will flood your bloodstream. They include such delights as benzene, methanol, acetaldehyde and hydrogen sulfide, all of which are “highly toxic.” Of course they are not toxic in the dose found in the soup. But should you look for them in the urine, thanks to our sophisticated analytical techniques, you would find them. Nobody bothers to look, because these chemicals are not deemed important, after all, they are “natural,” and nobody has a political interest in banning chicken soup. The story, however, is different when it comes to compounds such as phthalates.
These widely used chemicals make plastics, mostly polyvinyl chloride (PVC), soft and pliable, so they find extensive use in medical tubing, blood bags, catheters, children’s toys, vinyl flooring, food wraps, shower curtains, sex toys, automobile interiors, adhesives, sealants, cosmetics, printing inks and paints. They are also used in many personal care products to retard the loss of fragrance as well as in the coatings of many medications where they protect the ingredients from being degraded by stomach acid. This ensures safe passage through the stomach to the small intestine where the active ingredient can be absorbed. It comes as no surprise that with phthalates being ubiquitous, they can be detected in our bloodstream and urine. The question is whether this has any significant health consequences.
Phthalates constitute a large group of compounds with different properties. Some, especially the lower molecular weight ones, have been shown in rodent trials to interfere with the function of androgens, the male hormones. A human study made a big splash with its finding that women who had higher blood levels of phthalates gave birth to male babies with a reduced distance between the anus and the genitals, seemingly a consequence of hormonal disruption. Phthalates have also been linked with decreasing sperm counts, neurodevelopmental impairment in children and increased risk of asthma and allergies. However, these are all associations and are not proof of a cause-and-effect relationship. The presence of a chemical cannot be equated to the presence of risk. But such associations do mean that further investigation is warranted.
A couple of relevant studies have recently emerged. One identified 2,027 cases of childhood cancer among 1.3 million births in Denmark between 1997 and 2017 and assessed the use of medicines formulated with phthalates by the mother during pregnancy and by their offspring during childhood. The researchers found an association between low molecular weight phthalates and some childhood cancers, particularly osteosarcoma. But there are the usual confounding factors. Was the greater exposure to phthalates due to pregnant women and children taking more medications because of some health problem? In that case, the increased risk of cancer could be due to that issue. Also, there are many other components in drugs besides phthalates. Could these be a factor? Another study examined levels of phthalate metabolites in the urine and found higher levels in people taking dietary supplements. There was no implication of any link to disease, but the findings highlight that exposure to phthalates is multi-faceted.
While the evidence for phthalates being implicated in human ailments is inconclusive, given their possible hormone-disrupting properties and their presence in body fluids, a reduction in exposure is in order. Some of the more troublesome phthalates have been removed from products by manufacturers, but a greater emphasis on replacing phthalates with alternatives is needed.
Unfortunately, there is not a whole lot that consumers can do. The main exposure to phthalates is likely through food, from the packaging and plastic equipment used in processing. A diet that relies less on processed foods reduces exposure, as does avoidance of scented cleaning agents and personal care products. Phthalate-free shower curtains, floor tiles and plastic toys are available. Keep in mind, though, that phthalates are just one family of compounds about which safety issues can be raised. Bisphenols, perfluoroalkyl substances, parabens and pesticide residues are others.
But remember that chicken soup made with fresh vegetables and organic, free-range chicken can still deluge the urine with plenty of compounds that could be vilified the same way as phthalates if one cared to make the effort. You do put parsnips in your soup, right? Well they contain psoralens, compounds that are not destroyed by cooking and have carcinogenic potential. They will have a higher concentration in the urine than phthalates. This is not to suggest that concern about phthalates is unwarranted, just that given the thousands of naturally occurring and synthetic compounds to which we are regularly exposed, it should be kept in perspective. When it comes to phthalates, there is no raging fire, but there may be some smoldering twigs.
