In environmental science, the term “Dirty Dozen” refers to which of the following?

In environmental science, the term “Dirty Dozen” refers to 12 persistent organic pollutants (POPs) that are highly toxic, resistant to environmental degradation, and can accumulate in the fatty tissues of living organisms. These pollutants were identified under the Stockholm Convention on Persistent Organic Pollutants, an international treaty aimed at protecting human health and the environment from harmful chemicals.

The 12 chemicals in the Dirty Dozen include substances such as DDT, aldrin, dieldrin, chlordane, endrin, heptachlor, hexachlorobenzene (HCB), mirex, toxaphene, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans. They are used in agriculture, industry, and household products and are extremely persistent, meaning they do not easily break down in the environment.

These pollutants are harmful because they bioaccumulate in organisms and biomagnify up the food chain, leading to higher concentrations in predators, including humans. Long-term exposure can cause cancer, reproductive disorders, immune system damage, and developmental issues. POPs can travel long distances, contaminating areas far from their source.

Other options in the MCQ are incorrect:

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  12 most harmful greenhouse gases are not called the Dirty Dozen; greenhouse gases are a separate environmental concern.

  
  


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  12 ozone-depleting substances are different chemicals regulated under the Montreal Protocol, not the Dirty Dozen.

  
  

Understanding the Dirty Dozen is essential in environmental science for learning about toxicology, pollution control, international chemical regulation, and sustainable development. These chemicals illustrate the impact of human activity on the environment and emphasize the importance of global cooperation in reducing persistent pollutants.