Environmental health risks: an overview


What are the environmental health risks?

Humans share an interactive relationship with the environment. The biological, physical, chemical, biomechanical and psychosocial factors of the environment affect humans, which in turn exert an impact on the environment. Potentially, this interactive relationship exposes humans to environmental health risks. These include any environmental condition or factor that could result in illness, injury or death.

Environmental health risk. Image Credit: trekandshoot / Shutterstock.com

Environmental risks can have a direct or indirect impact on public health, and their impact varies from subtle to acute. Here are some examples :

The Bhopal disaster in India, 1984

A gas leak incident at a pesticide factory in Bhopal resulted in half a million people being exposed to methyl isocyanate gas, a highly toxic irritant material. 200,000 people have been poisoned, causing acute lung, kidney and liver disease, and more than 2,000 have died.

Minimata disease, Japan, 1956

A neurological disease first identified in the town of Minimata, caused by severe mercury poisoning. It was caused by the release of mercury from industrial waste from a chemical plant into the sea for thirty years. It entered the food chain via fish and shellfish, causing human death for many decades and congenital disease.

Use of pesticides, California, 1985

The insecticide aldicarb, a carbamate used to control insects, spiders and ticks, has been used inappropriately on a watermelon farm. When ingesting watermelon, around 1000 people developed gastrointestinal, muscle and autonomic effects.

Types of environmental risks

The hazards can be classified as follows:


Conditions, equipment or substances that endanger physical security. They include fire, radiation, poorly managed or poorly maintained machinery.


Organisms dangerous to humans, including parasites, viruses and toxins produced by organisms. This risk group is responsible for the majority of human illnesses, including HIV, hepatitis, cholera and tuberculosis.


Including solid, liquid and gaseous chemicals, these hazards are present when humans are exposed to harmful chemicals in their environment. They cause acute (as in Bhopal) or chronic (as in Minimata) health effects and can be inhaled, ingested or exposed through skin contact.


The term culture refers to the ideas and customs of a particular society, some of which can be harmful to health. Examples include the practice of female genital mutilation and open defecation.


Social factors such as poverty, obesity and drug addiction can lead to physical and mental dissatisfaction and chronic disease.

Environmental pollution as a danger

Pollution can be defined as any substance or form of energy, including sound, heat or radiation that contaminates the environment and causes damage to the ecosystem by promoting change in the environment.

The main pollutants include air, water and land pollution and occur when the addition of the pollutant occurs at a rate faster than the dispersion of the pollutant.

How to manage the hazards?

Managing the impact of environmental risks involves the use of monitoring and control techniques. Establishing and implementing routine measures to monitor changes in the environment or public health, by promoting early identification and response, can reduce the risk of hazards.

Monitoring can use data from a variety of sources, including health data, biomonitoring data, and emission inventories. Controls require setting thresholds for acceptable exposure levels and establishing what level of control is required to keep exposure below said threshold.

What environmental risks are under control?

Water and food

In the developed world, rigorous quality standards for the physical, biological and chemical qualities of drinking water are established and controlled in all water treatment and distribution networks. These tests include pH levels, dissolved metals and metalloids such as lead or mercury, chlorination byproducts, and antigens such as E coli.

Testing in the food industry takes an approach based on the principles of Hazard Analysis and Critical Control Points (HACCP), which seeks to identify potential danger points and apply actions to eliminate the hazards or reduce them to safe levels. The three main food hazards are microbiological, chemical and physical.


Air quality has a direct and significant impact on respiratory health. The main goal has been to protect outdoor air quality by controlling pollutants such as carbon monoxide, nitrogen dioxide and lead that can cause chronic public health problems.

Over the past hundred years, attention has turned to “air toxics”, organic chemicals made up of molecules such as carbon and hydrogen, and more recently to the control of greenhouse gases.

Ionizing and electromagnetic radiation

Ionizing radiation is a type of energy released in the form of electromagnetic waves, such as gamma or X rays, or particles such as neutrons. Although ionizing radiation has many useful applications including medicine, industry and agriculture, it also presents the potential for health risks if not properly contained.

Beyond safe limits, radiation exposure can cause acute effects such as radiation burns, skin redness and radiation syndrome, a set of serious health effects that can lead to death.

The references:

  • D’Haenens, JP, McDonald, KW, Langley, RL, Higgins, SA, Scott, R., Farquhar, PN, & Meggs, WJ (2013). Aldicarb: a series of cases of carbamate toxicity transmitted by watermelon. Agromedicine review, 18(2), 174-177. https://doi.org/10.1080/1059924X.2013.766141
  • Kamiya, K., Ozasa, K., Akiba, S., Niwa, O., Kodama, K., Takamura, N., Zaharieva, EK, Kimura, Y., & Wakeford, R. (2015). Long-term health effects of radiation exposure. Lancet (London, England), 386(9992), 469-478. https://doi.org/10.1016/S0140-6736(15)61167-9
  • www.cdc.gov. (2020). National environmental public health monitoring | Follow-up | NCEH | CDC. [online] Available at: https://www.cdc.gov/nceh/tracking/.
  • Food Standards Agency (2017). Hazard Analysis and Critical Control Points (HACCP). [online] Food Standards Agency. Available at: https://www.food.gov.uk/business-guidance/hazard-analysis-and-critical-control-point-haccp.


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