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What is the difference between pollutants and contaminants?

By Jennifer Anderson | Last updated: September 25, 2021

Pollutants are a category of contaminants. Specifically, they are contaminants that have been introduced into the environment beyond permissible limits and measurably cause harm to the environment.

Contaminants are a broader category of substances that are toxic, persistent, and likely to bio-accumulate, contaminating other substances or the environment.

To understand the difference clearly, let's consider each individually.


What Are Pollutants?

Pollutants are any substances, such as chemicals or waste products, introduced into the environment that render natural resources like air, water, and soil unsuitable or harmful for their typical purposes.

Pollutants are the result of direct or indirect human introduction of substances into the environment. These pollutants result in harm to living organisms and pose acute or chronic hazards to human health.

Common polutants include:

  • Nitrogen oxides (NOx)
  • Sulfur oxides (SOx
  • Particulate matter
  • Ground-level ozone (O3)
  • Volatile organic compounds (VOCs)
  • Mercury (Hg)
  • Peroxyacyl nitrates (PANs)

Individual pollutants can, moreover, be characterized either as primary or secondary pollutants:

  • Primary Pollutants are released directly into the environment.
  • Secondary Pollutants are the result of primary pollutants and external factors.

Exposure to pollutants in the workplace often occurs through air pollution, including fumes and airborne dust particles.

What Are Contaminants?

Contaminants are extraneous, often infectious and harmful, substances in concentrations higher than their natural levels. This includes any foreign substance introduced into the environment through human activity or natural processes.

Contaminants can be chemical, biological, radiological, or physical and can be found in the air, water or soil. Contaminants in the workplace can pose a risk to workers, including the development of chronic health complications.

These can be surface contaminants, like molds and fungi, or airborne contaminants like vapors and gases.

Some of the most common workplace contaminants are:

  • Lead: Common in the metal and battery industries. Overexposure can cause fatigue, nausea, weakness, and memory loss.
  • Silica: Common in construction projects involving concrete, gypsum, or plaster, as well as in automotive repair shops. Overexposure can cause lung cancer, pulmonary tuberculosis, autoimmune disease, and COPD.
  • Beryllium: Common in the tool and die-making industry, welding, and ceramics. Overexposure can cause exhaustion, chest pain, weight loss, and eye irritation.
  • Hexavalent Chromium: Common in steel manufacturing, blazing, and thermal cutting, as well electroplating and textile dyeing. Overexposure can cause respiratory tract infection, lung cancer, and allergies.
  • Benzene: Common in the rubber processing industry, gas stations, and steel plants. Effects of overexposure are dizziness, headache, nausea, eye irritation, and skin irritation.
  • Formaldehyde: Common in industries that require the use of resins and dyes. Overexposure can cause coughing, sneezing, and respiratory tract irritation.
According to the Occupational Health and Safety Administration (OSHA), employers should provide appropriate personal protective equipment to employees who may be exposed to pollutants or contaminants in their work environment.

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