Essay on POPs - Persistent Organic Pollutants (English)

            Dear Hospital Director,

          During the last board meeting you brought up your objective of making our hospital a model establishment in terms of sustainability and respect for the environment, especially through reducing the amount of garbage produced. Indeed, according to the American Hospital Association (AHA), US hospitals produce more than 5 million tons of waste each year, a rising value due to new medical technologies using more plastic and disposable products.

        I want to raise your awareness about an issue that you might not be aware of while improving waste management: the production of persistent organic pollutants (POPs) by medical institutions. In this note, I will answer several questions: What are persistent organic pollutants and the issues with those products, and most importantly, can health institutions take actions on POPs to reduce environmental risks?

What are persistent organic pollutants?

         Of all the pollutants discharged in the environment by human activity, persistent organic pollutants are among the most dangerous. They are very toxic organic chemical compounds that persist in the environment, bioaccumulate in fatty tissues, travel long distances and migrate to cold climates.

           POPs are characterized according to their source in three categories: pesticide POPs, industrial POPs, and byproducts. It is against the latter that you can play a role since some, as dioxins and furans, are unintentionally produced by processes as incomplete combustion of hospital garbage.

               An international legally binding treaty to ban POPs was signed in 2001 in Stockholm by 87 countries: the Stockholm Convention. It implements measures to control the production, trade and use of POPs. The US is not yet a Party to the Convention but the latter is important in controlling those pollutants at the national and global level.

              Twelve POPs, the « dirty dozen », were first targeted by international action through the Convention: aldrin, dieldrin, endrin, chlordane, DDT, heptachlor, mirex, toxaphene, hexachlorobenzene, polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins and polychlorinated dibenzofurans. Even though they are subject to restriction or banned in many countries their persistence makes them remain critical threats.

                Usual pollutants tend to stay next to their source and can often be managed by reducing them to levels at which they are assimilated by ecosystems without harm. However, POPs are different: they travel long distances, as you can see on diagram n°1 (Annex), and when they enter ecosystems they do not dilute but rather increase in intensity as they move up the food chain, a phenomenon called bioaccumulation, illustrated in diagram n°2 (Annex).

What are the effect of POPs in the environment?

               POPs have widespread effects on the environment. They affect various areas, from polar regions to the Great Lakes in America. Moreover, effects that were first observed in wildlife species are now also seen in humans. However, studying the effects of individual POPs is difficult because their impacts are rarely isolated.

          First, POPs negatively affect wildlife. For example, the US Environmental Protection Agency (EPA) showed that many predators as eagles, trouts and turtles suffered health effects such as population decline, deformities, reproductive effects, cancers, neurological issues and hormone system dysfunction as illustrated by the masculinization of females and feminization of males.

             POPs also affect humans. We are mostly exposed to those pollutants through food - especially food with much animal fat as fish and meat - and through inhalation and dermal contact. POPs’ effects can be triggered at extremely low concentrations. There can be many years between exposure and outcome in individuals, and sometimes a transgenerational leap: exposure in the parent leads to effects in the children. Hence it is difficult to identify the relationship between exposure and effects and that is why it is hard to diagnose health outcomes linked to POPs, which adds to the invisibility of this public health problem. Nevertheless now there exists scientific evidence that certain POPs are associated with serious serious health issues in humans. Among these outcomes are cancer, neurobehavioral impairment as attention deficits, immune system disruptions, reproductive problems, diabetes, etc. The alteration of the endocrine system is the principal mechanism responsible for those issues.

Challenges of POPs control

                 Although research has greatly increased our knowledge of POPs’ impacts on people and wildlife, controlling those pollutants remains challenging due to several controversies.

       First, there is a crucial debate about DDT, (Dichlorodiphenyltrichloroethane). First used during the Second World War as insecticide against mosquitoes, the vectors of malaria and typhus, it was then promoted as a wonder chemical for agriculture. However, in 1962, the biologist Rachel Carson published Silent Spring, a book describing the impact of DDT on the environment, for instance its toxicity to birds where it affects negatively reproduction through eggshell thinning, and to humans, after a long exposure, through health effects including more risks of cancer and diabetes, reproductive issues and neurological disorders. DDT was banned in the US in 1973 and more globally in 2001 by the Stockholm Convention. Some critics claimed that the restricted use of DDT implied by the treaty was responsible for the chronic death toll from malaria. However in reality using DDT is still permitted in small quantities in countries that need to control mosquitoes, with support for a transition to safer alternatives.

                Another controversy is that certain POPs were mentioned in the Stockholm Convention, but were not part of the banned « dirty dozen », such as perfluorooctone-sulfonates (PFOs), for instance used as stain repellents. Their properties - as high resistance to environmental breakdown - can make them dangerous, as other POPs initially banned. PFOs are controversial because of the economic and political impact their ban could can have among various countries and businesses, especially in newly industrialized nations which do not have invested in alternative chemicals or methods yet.

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