IN THE 21st century, humanity faces a paradox of its own making. The same chemistry that fuels economic growth, medical advancement and industrial innovation has silently filled the planet with invisible poisons. From pesticides in the soil to microplastics in the ocean and pharmaceuticals in our rivers, a complex web of synthetic compounds now threatens the foundations of ecological and human health.
Chemical pollution has become an unacknowledged driver of planetary instability alongside climate change and biodiversity loss. Persistent organic pollutants, polychlorinated biphenyls and pharmaceuticals and personal care products stand as three of the most urgent threats in this crisis. They represent the chemical footprints of modern life produced in one part of the world, transported across borders and deposited in the most remote corners of the planet.
Nowhere is this more evident than in South Asia, a region where industrialisation has raced ahead of environmental governance. From the industrial corridors of Bangladesh and India to the informal waste sites of Pakistan and Nepal, the chemical legacy of unregulated growth is visible in water, soil and, even, human blood. The crisis is both local and global and its molecules cross oceans, but its impacts are acutely felt in the global south.
Persistent organic pollutants are a group of toxic chemicals known for their resistance to degradation, their ability to bioaccumulate in living organisms and their capacity to travel long distances through air and water. Classic persistent organic pollutants include industrial and agricultural compounds such as dichlorodiphenyltrichloroethane, aldrin, dioxins, furans and polychlorinated biphenyls. Newer variants such as per- and polyfluoroalkyl substances have expanded the list. They are used in textiles, packaging, cookware and firefighting foams.
The unique danger of persistent organic pollutants lies in their longevity. Once released, these chemicals persist for decades in soil and sediment. Their semi-volatile nature allows them to evaporate in warmer climates, travel through the atmosphere and condense in cooler regions. The process is known as the 鈥榞rasshopper effect.鈥� As a result, Persistent organic pollutants have been found in the Arctic, in penguins of Antarctica and in the breast milk of mothers living thousands of kilometres from the nearest factory.
In South Asia, the legacy of these pollutants is deeply rooted in agricultural modernisation and industrial expansion. The heavy use of organochlorine pesticides in the Green Revolution left residues across the Indo-Gangetic plains, where they remain trapped in soil and groundwater. Tanneries in Bangladesh, textile dyeing units in India and unregulated open burning in Pakistan continue to emit dioxins and furans. The region鈥檚 warm climate and high humidity further accelerate volatilisation, creating a constant cycle of redistribution and exposure.
Human health consequences are equally alarming. Persistent organic pollutants interfere with endocrine systems, disrupt reproductive hormones, and generate reactive oxygen species that damage DNA. Chronic exposure has been associated with developmental disorders, immune suppression and cancers. In Bangladesh and India, several studies have detected dichlorodiphenyltrichloroethane and hexachlorobenzene residues in breast milk samples at concentrations exceeding WHO limits. The persistence of such chemicals in human tissue decades after their ban underscores both the resilience of the molecules and the weakness of regional regulatory systems.
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Industrial legacy
POLYCHLORINATED biphenyls embody the irony of industrial progress. Synthesised in the late nineteenth century and widely used through the mid-twentieth, polychlorinated biphenyls were once considered a technological miracle, ideal for transformers, capacitors and lubricants because of their stability and non-flammability. That same stability, however, made them virtually indestructible in nature. Chemically, polychlorinated biphenyls are made up of two benzene rings with varying chlorine atoms, forming 209 possible congeners. Some exhibit dioxin-like toxicity, while others interfere with metabolic processes in subtler ways. Their carbon-chlorine bonds resist microbial breakdown, oxidation, and hydrolysis, ensuring persistence in soils and sediments for centuries.
Despite a global ban under the Stockholm Convention on Persistent Organic Pollutants, polychlorinated biphenyls continue to leak into the environment through old equipment, demolition waste, ship-breaking and e-waste recycling. South Asia鈥檚 informal industrial sectors have become significant secondary sources. The ship-breaking yards of Chattogram in Bangladesh, Alang in India and Gadani in Pakistan collectively process millions of tonnes of scrap metal each year. Many of these ships contain polychlorinated biphenyl-laden insulation, paints and hydraulic fluids. Without proper disposal infrastructure, these contaminants seep into coastal soils and marine ecosystems.
In aquatic systems, polychlorinated biphenyls bind strongly to organic matter and accumulate in fish and shellfish. Once ingested, they lodge in human adipose tissue, where they remain for years. They act as endocrine disruptors, alter thyroid function and impair neuro-development in infants. The International Agency for Research on Cancer classifies polychlorinated biphenyls as Group 1 carcinogens. Bangladesh鈥檚 environment department, under its PCB management and phase-out plan, has identified more than 15,000 tonnes of polychlorinated biphenyl-contaminated oil and equipment awaiting a safe disposal. Yet, resource constraints and limited technical capacity have slowed progress. Across the region, the challenge is the same: dismantling the infrastructure of the past without creating new environmental catastrophes.
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Pharmaceuticals, personal care products
WHILE persistent organic pollutants and polychlorinated biphenyls represent the toxic legacy of industrialisation, pharmaceuticals and personal care products embody a more recent but equally insidious form of pollution. These are chemicals designed to interact with biological systems: antibiotics, painkillers, hormones, disinfectants and cosmetics that now infiltrate the environment through sewage, hospital waste and agricultural runoff. Unlike traditional pollutants, pharmaceuticals and personal care products are biologically active even at low concentrations. Wastewater treatment plants, especially in developing countries, are not equipped to remove these compounds. They pass through treatment systems, enter rivers and re-enter the food chain. In countries where treated wastewater is used for irrigation, pharmaceutical residues are absorbed by crops and ultimately ingested by humans.
Recent studies across South Asia have showed alarming levels of contamination. Rivers near pharmaceutical manufacturing hubs in India and Bangladesh contain antibiotic concentrations up to 300 times the safe limits. Painkillers like diclofenac, once widely used in veterinary medicine, have nearly wiped out vulture populations across the subcontinent by causing kidney failure in birds feeding on treated carcasses. In Bangladesh鈥檚 Buriganga and Turag, residues of paracetamol, ibuprofen and antibiotics have been found alongside high loads of heavy metals and microplastics. The environmental and health implications are vast. Antibiotic residues in water and soil accelerate the emergence of antimicrobial resistance, a global health emergency already claiming millions of lives annually. Endocrine-disrupting compounds such as parabens and triclosan alter reproductive behaviour in fish and amphibians. Synthetic musks and fragrances accumulate in sediments and aquatic organisms, affecting biodiversity and ecosystem functioning.
The complexity of pharmaceuticals and personal care products lies not only in their diversity but also in their constant renewal. Every year, thousands of new chemical formulations enter the market, a few of which undergo comprehensive environmental testing. As a result, regulation lags far behind innovation, creating a chemical treadmill that outpaces policy intervention.
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Unequal burden
ALTHOUGH these pollutants differ in origin and chemistry, their pathways converge in a shared pattern of persistence, mobility, and inequality. Persistent organic pollutants volatilise and settle through global atmospheric circulation; polychlorinated biphenyls seep from industrial residues into aquatic food webs; pharmaceuticals and personal care products flow invisibly through wastewater and agricultural soils. Together, they constitute a transboundary crisis that transcends geography yet disproportionately impacts the developing world. South Asia bears a double burden. The region鈥檚 rapid industrialisation and urbanisation generate massive chemical waste while inadequate treatment infrastructure allows pollutants to escape into the environment unchecked. The warm climate enhances volatilisation and dispersion while dense populations increase exposure risks. Informal industries, lacking regulation and safety measures, amplify the danger for workers and nearby communities.
This inequity extends to global governance. The same industrial nations that once exported toxic chemicals now outsource manufacturing to the global south. The result is a shift, not a solution chemical burdens migrate geographically but remain embedded in global supply chains. The promise of sustainable development remains hollow if environmental justice is absent from the equation.
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Policy and governance
THE scientific understanding of chemical pollution has advanced dramatically, but policy responses remain fragmented. The Stockholm Convention and the Basel Convention provide frameworks for managing hazardous substances and waste, yet enforcement in South Asia is uneven. Monitoring systems are weak, laboratories underfunded, and coordination among environmental, health, and industrial ministries is often lacking.
A regional approach is urgently needed. The South Asian Association for Regional Cooperation could play a pivotal role by establishing a shared chemical monitoring network, harmonizing data collection, and supporting capacity building for analytical laboratories. Regional guidelines for industrial waste management, particularly in the textile, pharmaceutical, and electronic sectors, could reduce duplication and raise collective standards.
Domestically, South Asian countries must move from reactive cleanup to proactive prevention. Strengthening environmental legislation, integrating chemical safety into industrial licensing and enforcing extended producer responsibility can significantly reduce leakage. Wastewater treatment infrastructure must be upgraded to include advanced technologies such as activated carbon filtration, ozonation and membrane bioreactors capable of removing trace organic contaminants.
Equally vital is the investment in green chemistry that designing molecules and processes that are biodegradable, non-toxic, and resource-efficient. Research institutions in Bangladesh, India and Sri Lanka have already piloted projects on bio-based surfactants, eco-friendly dyes and enzyme-based industrial catalysts. Scaling such innovations can align industrial growth with ecological resilience.
Public awareness and citizen engagement must complement regulatory measures. Community-based monitoring, environmental journalism, and academic outreach can translate technical knowledge into civic action. As the media increasingly cover issues such as river pollution and e-waste, a new culture of environmental accountability is emerging across South Asia.
The chemical crisis is not a single-issue problem. It is a symptom of humanity鈥檚 fragmented relationship with nature. Every molecule released into the environment is a record of policy failure, technological excess, or social neglect. Addressing it demands a holistic vision that unites health, environment, and industry under the umbrella of planetary health. For South Asia, the opportunity lies in transforming vulnerability into leadership. By integrating pollution control into national development plans, investing in regional monitoring networks, and adopting global best practices, the region can demonstrate how sustainable growth need not depend on chemical compromise.
Governments must recognise that pollution is not merely an environmental cost but an economic liability. The long-term healthcare costs, loss of biodiversity and declining productivity from soil and water degradation far outweigh short-term industrial gains. Integrating chemical safety into trade, investment and energy policies will not only protect public health but also strengthen global competitiveness. The future of chemical governance must be anticipatory, not retrospective. This means regulating new compounds before they become pollutants, encouraging industries to disclose chemical inventories, and aligning consumer awareness with corporate responsibility. It means acknowledging that the molecules we release today will shape the health of generations yet unborn.
The story of chemical pollution is the story of modern civilisation: a tale of ingenuity turned inadvertent harm. Persistent organic pollutants, polychlorinated biphenyls and pharmaceuticals and personal care products show how invisible molecules can erode visible systems: soil fertility, public health and ecological stability. In South Asia, where economic growth is both a necessity and a challenge, the choice between prosperity and pollution must no longer be seen as inevitable. Global chemical governance cannot succeed without regional solidarity. South Asia must lead by example, through scientific collaboration, policy innovation and moral commitment to planetary stewardship. The chemistry that once defined progress must now be redefined through responsibility. The invisible crisis is already upon us, but it need not be irreversible.
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Arghya Protik Chowdhury ([email protected]) is a student of environmental science at the Bangladesh University of Professionals.
