Pollution

Primary reference(s)

UN data, no date. Pollution. Environment Glossary / United Nations Statistics Division. Accessed 23 October 2020.

Additional scientific description

Our food, air and water expose us to a complex mixture of chemicals and materials (UNEP, no date a).

These chemicals have a wide range of effects on health. In 2012, the World Health Organization (WHO) estimated that 23% of all deaths worldwide, amounting to 12.6 million people, were due to environmental causes; with 90% occurring in low- to middle-income countries (UNEP, 2021). In the same year, the burden of disease from environmental factors related directly to pollution in terms of death, illness and disability was estimated at 345 million Disability Adjusted Life Years (UNEP, no date a). More recently, a study indicated that pollution is currently the largest environmental cause of disease and death, responsible for an estimated 9 million premature deaths globally in 2015 (Landrigan et al., 2017). With world population growing, the numbers of vulnerable groups exposed to pollutants will increase unless urgent pollution abatement policies are implemented, and actions taken at the local level (UNEP, no date a).

Pollution can have a disproportionate and negative effect on the poor, the disadvantaged and the vulnerable. Pollution constitutes a significant impediment to achieving health, well-being, prosperity and the sustainable development goal of ‘leaving no one behind’ (UNEP, no date a).

There is a critical need for system-wide transformations to prevent, reduce and control pollution, toward greater resource efficiency and equity, circularity and sustainable consumption and production, and improved ecosystem resilience to support cleaner and more sustainable development (UNEP, no date a).

Metrics and numeric limits

Not identified.

Examples of drivers, outcomes and risk management

Pollution is one of the great existential challenges of the Anthropocene epoch (Landrigan et al., 2017). Pollution, especially pollution caused by industrial emissions, vehicle exhausts, and toxic chemicals, has increased sharply in the past 500 years, and the greatest increases today are seen in low-income and middle-income countries (Landrigan et al., 2017). Many organisations including the United Nations Environment Programme (UNEP), in partnership with other United Nations organisations, member states, scientists and communities at all levels has developed programmes addressing air pollution, water contamination, marine pollution, chemicals, plastics and waste and space debris. Brief summaries follow.

Air pollution: Killing an estimated 7 million people per year, air pollution is currently the biggest environmental health risk. Airborne pollutants are responsible for about one third of deaths from stroke, chronic respiratory disease, and lung cancer, as well as one quarter of deaths from heart attack. Air pollution is also strongly influencing climate and is generated from various sources, from cookstoves and kerosene lamps to coal-fired power plants, vehicle emissions, industrial furnaces, wildfires, and sand and dust storms. The problem is most acute in urban areas, particularly in Africa and Asia. In low- and middle-income countries, 98% of cities with more than 100,000 inhabitants fail to meet the WHO air quality guidelines. Addressing air pollution can bring significant benefits for economies, human health, and the climate. This underlies global efforts by UNEP to tackle air pollution by supporting cleaner fuels and vehicles, inspiring individuals and city leaders to act, strengthening laws and institutions, and developing affordable technologies to monitor air quality (UNEP, no date b).

Water contamination: UNEP reports that once water is contaminated, it is difficult, costly, and often impossible to remove the pollutants (UNEP, no date c). Currently, 80% of global wastewater goes untreated, and is contaminated by a wide range substances, from human waste to highly toxic industrial discharges. The type and amount of pollutants in freshwater determines its suitability for human uses such as drinking, bathing, and agriculture. Pollution of freshwater ecosystems can also impact the habitat and quality of life of fish and other wildlife. This can include pathogens (largely from human and animal waste), organic matter (including nutrients from agricultural run-off such as nitrogen or phosphorus), chemical pollution (from irrigation, domestic wastewater and runoff of mines into rivers) and salinity. Plastics, and chemicals of emerging concern such as certain pharmaceutical products, are issues for which their extent and impacts on freshwater are largely unknown. A 2016 preliminary assessment of water quality in rivers in Latin America, Africa and Asia, A Snapshot of the World’s Water Quality (Ringler, et al., 2016), estimated that severe pathogenic pollution affects around one third of all rivers, severe organic pollution around one seventh of all rivers, and severe and moderate salinity pollution around one-tenth of all rivers in these regions (UNEP, no date c).

Marine pollution: Municipal, industrial and agricultural wastes and run-off account for as much as 80% of all marine pollution (UNEP, no date e). Sewage and waste water, persistent organic pollutants (including pesticides), heavy metals, oils, nutrients and sediments - whether from rivers or discharged directly into coastal waters – can have significant impacts on human health and coastal ecosystems. The result is more carcinogens in seafood, more closed beaches, more red tides, and more beached carcasses of seabirds, fish and even marine mammals. One billion people in developing countries depend on fish for their primary source of protein, making them vulnerable to the chemicals they carry. The first regional steps to address this widespread issue were taken in the Mediterranean, with the adoption of the Protocol on Land-Based Sources of Pollution in May 1980 (UNEP, 1980). Over the next two decades, this landmark agreement led to similar regional agreements in other Regional Seas (UNEP, no date d).

Chemicals, plastics and waste: As the world’s population approaches 8 billion, the need for sound management of chemicals and waste is increasing. UNEP promotes joint approaches to the environment and health that demonstrate the economic, environmental and health advantages of sound chemical management for all concerned to stimulate policies and investment to reduce chemical risks to health and environment (UNEP, no date e). By 2025, the world’s cities are forecast produce 2.2 billion tonnes of waste per year, more than three times the amount produced in 2009 (UNEP, no date e). An important chemicalgenerating pollution is plastic. The presence of plastic in the environment and in particular in marine sediments can be seen as a stratigraphic indicator of the Anthropocene era (Zalasiewicz et al., 2016). Plastic pollution has mostly been studied in marine ecosystems (e.g., Eriksen et al., 2014; Haward, 2018), including seabirds (Wilcox et al., 2015), but freshwater ecosystems (Blettler et al., 2018) and soil ecosystems (Chae and An, 2018) are also affected. The accumulation of plastic, especially micro- and nano-plastics is a threat to human health (e.g., Revel et al., 2018).

Space debris: Pollution also extends to the Lower Earth Orbit (LEO) where millions of pieces of debris are found. These are mostly of anthropogenic origin, such as pieces of space craft, flecks of paint from a spacecraft, parts of rockets, or satellites that are no longer working. These objects fly at high speed (up to 18,000 miles per hour) and together with the amount of debris present puts astronauts and equipment in space at risk. Some of the equipment at risk is essential to global communication and earth monitoring networks, including weather and hazard forecast and early warning systems (NASA, 2019). There are no international space laws to clean up debris in the LEO, from where it is expensive to remove space debris because there are almost 6000 tons of material in LEO. The NASA Orbital Debris Program began in 1979 in the Space Sciences Branch at the Johnson Space Center in Houston, Texas. The programme looks for ways to create less orbital debris, and designs equipment to track and remove debris already in space (NASA, 2019).

Risk management mechanisms for pollution/contamination prevention and control are essential and may include: local, national and global policies, strategies and legislation; planning and coordination (at all levels – national, subnational, local, including regional and transboundary); financial and human resources with a trained multidisciplinary workforce capacity; information and knowledge management for risk assessments, early warning and surveillance and technical guidance and support; mechanisms for risk communication; infrastructure support to include environmental and health services; and facilities for monitoring and evaluating drivers, impacts, outcomes and controls and reporting to local, national and international partners and organisations.

The WHO works closely with countries and partners to monitor and report on their emergency preparedness capacities for all hazards, including for chemical incidents relating to pollution and contamination. Surveillance of diseases of possible chemical etiology is a daily element in the WHO’s outbreak alert and response activities (WHO, 2020). Other health-related resources include the WHO Health Emergency and Disaster Risk Management Framework (WHO, 2019). This has been designed to help manage the recovery phase of a pollution incident where contamination has affected food production systems, inhabited areas and water environments, further information can be found in the UK Recovery Handbook for Chemical Incidents (PHE, 2020).