In a recent scientific study, it was discovered that rainwater in many areas around the world is contaminated with man-made chemicals known as Per- and Polyfluoroalkyl Substances (PFAs). These compounds are often referred to as ‘Forever chemicals’ due to their durability, persisting in the environment for extended periods.
The Stockholm Convention and Persistent Organic Pollutants
The Stockholm Convention is an international treaty aimed at protecting human health and the environment from harmful substances known as persistent organic pollutants (POPs). These are chemicals that remain in the environment for a long time, spread over large geographical areas, accumulate in living organisms’ fatty tissues, and pose toxic risks to humans and wildlife. India ratified the Stockholm Convention in 2006 under Article 25(4), opting out by default from amendments made to various Annexes of the treaty unless specific ratification or approval is granted by the UN depositary.
Understanding Per- and Polyfluoroalkyl Substances (PFAs)
PFAs are synthetic chemicals used in the manufacture of various products, including nonstick cookware, water-resistant clothing, stain-resistant fabrics, cosmetics, and firefighting foams. They resist grease, water, and oil, and can migrate to soil, water, and air during their production and usage. PFAs persist in the environment for a long time, and some can accumulate in people and animals through repeated exposure.
Harmful Effects of PFAs
PFAs have been associated with several health risks, such as reduced fertility, developmental issues in children, hormonal interference, elevated cholesterol levels, and an increased likelihood of certain cancers. Recent studies suggest that consistent low-level exposure to certain PFAs can hinder the human body’s ability to produce antibodies after vaccination.
Methods to Remove PFAs
Various methods have been developed to remove or destroy PFAs.
Incineration
Incineration is a commonly used method for destroying PFAs. However, most PFAs are remarkably resistant to combustion due to the strong bond between carbon and fluorine atoms, which must be broken for successful incineration.
Supercritical Water Oxidation
One method developed by scientists is supercritical water oxidation, which uses high temperatures and pressures to trigger chemical reactions that can successfully break down hazardous substances like PFAs.
Plasma Reactors
Researchers are also examining the use of plasma reactors, which employ water, electricity, and argon gas to degrade PFAs.
Filtration System
Filtration systems using activated carbon in rainwater harvesting systems can also help remove these chemicals. The activated carbon must be replaced regularly, and the contaminated material must be properly disposed of.
Pollutants in Indian Drinking Water
The issue of drinking water contamination is not new. A question from the 2013 UPSC Civil Services Examination highlighted various potential pollutants in Indian drinking water, including arsenic, fluoride, and uranium. Contamination sources range from natural deposits to human activities such as groundwater-table decline and nitrate pollution. Understanding and mitigating these problems is essential for public health and environmental protection.
