Persistent organic pollutants are a group of hazardous synthetic chemicals that resist environmental degradation, leading to their long-term presence in various ecosystems.

These compounds include a variety of preparations including polychlorinated and polybrominated biphenyls, dichlorodiphenyltrichloroethane, dioxins, furans, and certain organochlorine pesticides. Due to their physicochemical properties, POPs have the potential to bioaccumulate and their effect to biomagnify, posing a threat to human health through exposure via food, air, and water.

∎ Polychlorinated biphenyls orPCBs were widely used in electrical equipment.

∎ Polybrominated diphenyl ethers or PBDEs were utilised as flame retardants in various consumer products,

∎ Dichlorodiphenyltrichloroethane, or DDT, was once employed as an insecticide,

∎ Dioxins and furans are by-products of waste incineration and industrial processes,

∎ Organochlorine pesticides have historically been used in agriculture.

Human exposure to POPs occurs through various pathways. Ingestion is the most significant route, primarily via the consumption of contaminated foods, especially animal-derived products high in fat as these products get stored in fat, called lipophilic. Inhalation of contaminated air near industrial or waste sites can also contribute to exposure, along with direct contact with contaminated soil and drinking water.

The T-fal story:

A prime example of a persistent organic pollutant is PTFE or Teflon, a non-stick coating developed and heavily used in the past by T-fal's cookware company. It has also been used in many other industries to make things like fire retardant garments and spill-resistant furniture.

While these properties were greatly welcomed and Teflon and Teflon-like products were quickly adopted in every household, concerns started to grow about their potential health risks. At high temperatures, or with repeated manipulation and washing, Teflon coatings can release POP fumes and particles which may be harmful if inhaled or swallowed.

A slew of lawsuits in American courts have taken place backed by clinical evidence of health harm by Teflon to certain individuals. They ended up forcing some manufacturers, including T-fal itself, to transition to PTFE-free non-stick coatings, which are considered safer.

The health effects of POPs

∎ Hormones disruption: POPs can mimic or block natural hormones, leading to hormonal imbalances. These disruptions can have significant effects on the development, growth, and functioning of various organs and systems.

∎ Reproductive disorders: exposure to certain POPs has been linked to reproductive disorders in both males and females. These disorders may include infertility, reduced sperm quality, incomplete pregnancies, and menstrual irregularities.

∎ Developmental and growth impairments: POPs can interfere with the normal growth and development of foetuses, infants, and children. Exposure to these chemicals during critical developmental stages could possibly result in physical impairments and congenital deformities.

∎ Neurotoxicity: certain POPs can harm the nervous system. This can manifest as impaired cognitive function, memory deficits, learning difficulties, and behavioural changes, especially in children.

∎ Immune system dysfunction: POPs have been shown to modulate the immune system, leading to reduced immune defence against infections and possible increased risk of autoimmune diseases like lupus.

∎ Cancer: some POPs, such as dioxins and certain PCBs, have been classified as carcinogens (substances that can cause cancer). Prolonged exposure to them can increase the risk of developing various types of cancer, including breast, prostate, liver, and others.

The global regulatory efforts against POPs

Global regulatory efforts and preventive measures against POPs have been implemented to address the widespread environmental and health concerns associated with these toxic chemicals. The primary international framework for addressing POPs is the Stockholm Convention on POPs.

This is a legally binding international treaty that aims to eliminate or restrict the use of 28 POPs. Parties to the convention are required to take measures to eliminate or reduce the release of these chemicals into the environment.

The Stockholm committee periodically reviews new substances to assess their persistence, bioaccumulation, and adverse effects on human health and the environment. If a substance meets these criteria, it may be added to the list of regulated POPs.

Each party to the Stockholm Convention is required to develop and implement a National Implementation Plan to identify and address the release of POPs within its territory. The NIP outlines specific policies and strategies to reduce or eliminate the future use and production of these chemicals, along with measures to manage and disposal of already present stockpiles and POP wastes.

The convention encourages the development and promotion of safer, technically and economically feasible alternatives to POPs. Best available techniques are identified and disseminated, to help parties transition to more environmentally friendly alternatives.

It also emphasises the importance of public awareness and education regarding the diverse risks associated with POPs.

• Joe Yammine, MD is a consultant cardiologist at the Bermuda Hospitals Board. The information here is not intended as medical advice or as a substitute for professional medical opinion. Always seek the advice of your physician