By Sharon Atieno

There is mounting scientific evidence showing how plastics are harming human health, more so, women and children, experts said during a side event at the ongoing 6th United Nations Environment Assembly (UNEA).

The latest research reveals the presence of microplastics- particles smaller than five millimetres derived from the degradation of plastics- in the human placenta, leading to concern about the health implications of the development of foetuses.

The report analyzed 62 placental tissue samples and found polyethylene, used in making plastic bags and bottles, as the most common plastic. This was followed by Polyvinyl chloride (PVC) and nylon.

A previous study conducted in 2020 showed similar results in four healthy pregnant women who had normal pregnancies and births in Italy. Microplastics were detected on both the foetal and maternal sides of the placenta and in the membrane within which the foetus develops.

Majority of the microplastics were identified to belong to polypropylene while the others were found to be used for man-made coatings, paintings, adhesives, plasters, finger paints, polymers and cosmetics and personal care products.

Besides the placenta, microplastics have been reported in arteries, meconium (first stool from a newborn), breastmilk and infant formula.

Speaking during the side event titled ‘Plastics poison and women’s health’, Yuyun Ismawati, Environmental Engineer and Co-founder Nexus3 Foundation observed that women are exposed to these chemicals through water, toothpaste, or other cosmetic products. The babies are exposed through breastfeeding and saliva due to their feeding habits.

According to Ismawati, no plastic chemical has been classified as safe, even recycled plastics including kitchen utensils and children’s toys are not safe as they have a lot of accumulated hazardous chemicals especially polymers which have been found in the new products.

“Scientists have only been able to identify 29% of chemicals (3,800) used in plastics as chemicals of concern. This is not because of toxicity but because they (chemicals) are unexplored and understudied,” she said, adding that there is a need to do more including developing a chemical inventory.

According to Dr. Marina Fernandez, Associate Researcher at CONICET Neuroendocrinology Lab, some of these chemicals of concern found in plastics are endocrine disrupting chemicals (EDCs)- they interfere with any aspect of hormone action.

“The endocrine system regulates all the functionality of the body including reproduction, thyroid function, growth, and any disturbances to any of these aspects can lead to disease,” she explained.

Some of these EDCs include phthalates, bisphenols, perfluorinated compounds (PFAS), brominated flame retardants (BFRs), UV stabilizers and alkylphenols among others.

Phthalates are additives used to produce or promote flexibility and to reduce brittleness in plastics. They reduce testosterone and estrogen levels, block thyroid hormone action, and have been identified as reproductive toxicants.

Bisphenols are monomers of polycarbonate plastics which is found in various products including shatterproof windows, eyewear, water bottles, and epoxy resins that coat some metal food cans, bottle tops, and water supply pipes. They can affect brain development and behavior. They are associated with adverse reproductive outcomes, thyroid dysfunction and cancers including breast, prostate, ovarian and endometrial.

Alkylphenols are used in many plastics as UV stabilizers. They disrupt reproductive systems. Occupational exposures are associated with a heightened risk of breast cancer.

On the other hand, PFAS are used in water and stain-resistant clothing and food contact wrappers. They affect the immune systems, liver and thyroid function, alter puberty and are associated with kidney, testicular, prostate and ovarian cancers.

BFRs are used to reduce flammability in plastic products. They disrupt male and female reproductive development, alter thyroid function and affect neurodevelopment.

UV stabilizers are additives used to protect plastic building materials, automotive parts, waxes, and paints from deterioration due to UV radiation. They can leach from food packaging materials into food. They disrupt the endocrine function.

“Endocrine Disrupting Chemicals act at very low levels, and in many cases, have effects that appear after the exposure has ended,” Dr. Fernandez said, adding that research has demonstrated that some of these chemicals are pervasive despite having adverse effects on the endocrine systems.

“Women are particularly vulnerable to their effect as exposure during critical periods of development have effects later in life or subsequent generations [due to exposure while in the uterus],” she added.

Dr. Fernandez called for global regulation of these chemicals in a harmonized way to protect human beings, health and the environment.

She also called for the need to reduce drastically the production of plastics and make plastics safer.