Plastic toxicity is back in the news with the Central Environment Ministry banning four types of plastics from the beginning of this month, following repeated calls to reactivate our antiquated laws to halt these poisonous emissions that continue to put the nation’s health at risk.
In addition to this Sri Lankans are also threatened by a danger of being exposed to another toxic agent- Aflatoxins recently discovered in some stocks of imported coconut oil.
The Sunday Observer spoke to Emeritus Professor of Forensic Medicine and Toxicology, Faculty of Medicine, University of Colombo, Senior Professor of Forensic Medicine, General Sir John Kotelawala Defence University, Ratmalana, Prof. Ravindra Fernando to share his expertise on these toxic emissions.
Excerpts …
Q. The surge in toxic emissions from plastics has led to a decision by the Environment Ministry to ban four types of plastics that reportedly adversely affect humans, animals and marine life as from April 2021. Is this is a timely decision?
A. Yes, I think it is a correct and timely decision to save the nation’s health and the environment.
Q. The four types of plastic and polythene related products named are: Disposable polythene and plastic, PET bottles (Poly Ethylene Teraphalate), lunch sheets (less than 20 microns) among others. What are the toxic elements in each of the three items?
A. Single-use plastics are goods made primarily from fossil fuel–based chemicals (petrochemicals) and should be disposed of right after use - often, in mere minutes. Single-use plastics are most commonly used for packaging and service ware, such as bottles, wrappers, straws, and bags.
As for PET bottles (Poly Ethylene Teraphalate), while generally considered a “safe” plastic, and does not contain BPA (bisphenol A), in the presence of heat it can leach antimony, a toxic metalloid, into food and beverages, which can cause vomiting, diarrhoea and stomach ulcers.
Q. Any other adverse effects that plastics in general affect humans?
A. Exposure to harmful chemicals during manufacturing, leaching in the stored food items while using plastic packages or chewing of plastic teethers and toys by children are linked with severe adverse health outcomes such as cancers, birth defects, impaired immunity, endocrine disruption, developmental and reproductive effects etc.
Q. ‘Single-use plastics?
A. Single-use plastics are a glaring example of the problems with throwaway culture. Priortising convenience over durability and quality and reliance on these plastics means we are accumulating waste at a staggering rate.
Q. The Ministry also lists cotton buds (non-medical). What are the harmful ingredients they contain that harm our bodies?
A. The use of cotton swabs in the ear canal has no associated medical benefits and poses definite medical risks. Cerumen (ear wax) is a naturally occurring, normally extruded, product of the external auditory canal that protects the skin inside the ear, serves beneficial lubrication and cleaning functions and provides some protection from bacteria, fungi, insects, and water.
Q. The last mentioned are inflatable plastic toys. Is this ban due to concern regarding toxicity in inferior quality plastic used or due to physical risks posed if given to young children?
A. A wide range of chemical additives are used in plastic products, including children’s toys, to obtain or optimise specific product properties, such as material hardness or elasticity, Widely applied types of additives are used as plasticizers or softeners (to increase plasticity or decrease viscosity), flame retardants (to prevent or inhibit ignition), surface-active substances (e.g., to create foam with specific properties), stabilizers, colorants and fragrances.
Q. Plastic bags and containers made of expanded polystyrene foam (commonly referred to as “Styrofoam is commonly used by housewives and mothers when packing their children’s food. What harmful effects can they have on the food? Does it include any food like sandwiches and cold foods or hot foods? Why?
A. Polystyrene contains the toxic substances Styrene and Benzene, suspected carcinogens and neurotoxins that are hazardous to humans. Hot foods and liquids actually start a partial breakdown of the Styrofoam, causing some toxins to be absorbed into our bloodstream and tissue. When used with food products, especially when heated, Styrofoam releases toxic chemicals into the food causing a contamination which can be hazardous to your health In addition, when exposed to sunlight,
Q. We often see cafes and takeaway places serving food such as sambols, pickles, as well as hot cooked gravy and curries into plastic bags for customers to take home. Is this a good practice?
A. When food is stored in plastic bags, these chemicals can ‘leach’ into the food and infest them. Studies have shown that these chemicals have been linked to tissue changes, genetic damage, early puberty and hormonal changes. Experts suggest switching to brown paper bags or high grade polyethylene bags for a ‘safer’ be?
Q. Are paper cups and paper plates a safe alternative?
A. The base paper for paper cups is called “cupboard”, and is made on special multi-ply paper machines. It has a barrier coating for waterproofing. The paper needs high stiffness and strong wet sizing. The cupboard grade has a special design for the cup manufacturing processes.
Q. What about plastic spoons and plastic cups?
A. Avoid cooking hot food with plastic spoons, spatulas and whisks because toxic chemicals ‘could leach into your dinner’, scientists warn. Keep your plastic utensils away from piping hot meals or risk ingesting a slew of toxic chemicals, health experts have warned.
Q. Sri Lanka has been described as a country where burning plastics, especially PVC is widely common. I understand that this leads to the emission of very toxic fumes. Name some of them.
A. Burning plastic creates harmful dioxins and if incinerators are inefficient, these leak into the environment. Toxins such as dioxins (including PCB’s) hydrogen cyanide, furans, hydrochloric acid, sulphuric acid may be released.
The golden rule for householders is never, ever burn plastic at home.
Q. What kind of diseases can be caused by long or short term exposure to these toxic fumes in general?
A. Burning plastic and other wastes releases dangerous substances such as heavy metals, Persistent Organic Pollutants, and other toxics into the air and ash waste residues. Such pollutants contribute to the development of asthma, cancer, endocrine disruption, and the global burden of disease.
Q. What is the impact on children?
A. A ground-breaking study analysing the effects of toxic chemicals in plastic children’s toys and consumer products on human cells demonstrated that toys made from some recycled plastics are toxic to humans and can significantly contribute to the dioxin daily intake level for children who mouth their toys.
Q. Those with respiratory problems?
A. The presence of micro plastics in human lung tissue was already demonstrated in the 1990s by scientists investigating lung tissue of cancer patients, who expressed their concern that plastic fibers may contribute to the risk of lung cancer.
Q. In pregnant women - will it harm the foetus?
A. A new study suggests that exposure to the toxic chemicals in plastic during pregnancy can impact your child’s health.
Q. What are the commonest types of plastics in the environment?
A. The most common single-use plastics found in the environment have been found to be, cigarette butts, plastic drinking bottles, plastic bottle caps, food wrappers, plastic grocery bags, plastic lids, straws and stirrers, other types of plastic bags, and foam take-away containers.
Q. Do you think there is an alternative to halt this trend in throwaway culture? How?
A. “Use and throw culture” is very common nowadays. It means using materials like-plastic cups and throwing after using it. Use and throw culture is the modern culture, i.e., the modern culture of buying things and using, and then, throwing it. Alternative to halt this trend is not to use such material.
Q. Various solutions such as ecofriendly bricks, roofing etc. have been suggested. Do you think this will bring a solution to the problem?
A. Clay bricks and blocks and clay roof tiles are natural products, because they are basically made of earth, water and fire.
Q. We now have one or two recycling plants that make use of throw away plastics to produce new products. Are they 100% effective?
A. Plastics can readily be molded into various products, which find uses in a plethora of applications. Every year, more than 100 million tons of plastics are manufactured across the globe. Around 200 billion pounds of new plastic material is thermoformed, foamed, laminated and extruded into millions of packages and products. Consequently, the reuse, recovery and the recycling of plastics are extremely important.
Q. At present there is a controversy over the contents of refined coconut oil with tests done locally of samples imported from abroad showing they contain a toxic agent called Aflatoxin and a call to ban all imported coconut oil. As an authority on poisons could you tell us more about this toxic element and how it impacts on the human body?
A. Aflatoxins pose a serious health risk to humans and livestock Aflatoxins are poisonous substances produced by certain kinds of fungi (moulds) that are found naturally all over the world. They can contaminate food crops and pose a serious health threat to humans and livestock. Most human exposure comes from nuts and grains.
Q. What foods contain aflatoxin?
A. The staple commodities regularly contaminated with aflatoxins include cassava, chillies, corn, cotton seed, millet, peanuts, rice, sunflower seeds, wheat, and a variety of spices intended for human or animal consumption.
Q. Can aflatoxins be killed by heat?
A. Aflatoxin is stable and heat resistant. It is not possible to inactivate aflatoxin by heating your product.
Q. How can it be prevented from entering the body?
A. Control measures are required both pre- and postharvest. The most long-term, stable solution to controlling pre-harvest aflatoxin contamination is through enhancing the ability of the crop to resist fungal infection and/or prevent production of aflatoxins by the invading fungus.
Q. How do you remove aflatoxin from your body?
A. Once the mycotoxins get into the body, they may cause permanent damage, since they are carcinogenic, mutagenic and teratogenic in nature. It cannot be removed from the body.
Q. Your comments on the present controversy? Should or should such products be allowed into our country?
A. They should not be allowed into Sri Lanka.
Q. Finally your message regarding reducing health risks of from plastic pollution in general to our readers.
A. We must reduce the use of plastic products as much as possible.