Pollution
What is pollution?
Pollution is the introduction of harmful materials into the environment (also known as a Pollutant, resulting in the loss of Biodiversity (loss of habitat), and having negative impact on health and living conditions. These harmful materials are called pollutants. Pollutants can be natural, such as volcanic ash. They can also be created by human activity, such as litter/trash or runoff produced by factories.
What are the 4 types of pollution?
The major kinds of pollution, usually classified by environment, are:
Modern society is also concerned about specific types of pollutants, such as noise pollution, radiation, light pollution, and plastic pollution.
PBT's
PBT's stand for Persistent, bioaccumulation and toxic substances. PBT's pollute or harm the environment. PBT's is a class with substances that have a high resistance to degradation, can accumulate in organisms throughout the food chain and have high toxicity to the environment, human and animal health. The aim is to minimize the amount of PBT's in the environment as much as possible. PBT is a unique classification of substances that certainly will impact the environment and animal and human health.
The three main attributes explained:
- Persistence
- Bioaccumulative
- Toxic
There are some international treaties around PBT's:
- The Stockholm Convention
- The POP protocol
- OSPAR Convention
Persistent Organic Pollutants (POPs)
POPs are a set of toxic chemicals that are persistent in the environment and able to last for several years before breaking down (UNEP/GPA 2006a). POPs circulate globally and chemicals released in one part of the world can be deposited at far distances from their original source through a repeated process of evaporation and deposition. This makes it very hard to trace the original source of the chemical (http://web.worldbank.org/). POPs are lipophilic, which means that they accumulate in the fatty tissue of living animals and human beings (http://www.unece.org/spot/s01.htm). In fatty tissue, the concentrations can become magnified by up to 70 000 times higher than the background levels (http://web.worldbank.org/). As you move up the food chain, concentrations of POPs tend to increase so that animals at the top of the food chain such as fish, predatory birds, mammals, and humans tend to have the greatest concentrations of these chemicals, and therefore are also at the highest risk from acute and chronic toxic effects.
“Dirty Dozen”. These is a group of 12 highly persistent and toxic chemicals which is called "the dirty dozen":
- Aldrin
- Chlordane
- DDT
- Dieldrin
- Endrin
- Heptachlor
- Hexachlorobenzen
- Mirex
- Polychlorinated biphenyls
- Polychlorinated dibenzo-p-dioxins
- Polychlorinated dibenzofurans
- Toxaphen
Many of the pesticides in this group are no longer used for agricultural purposes but a few continue to be used in developing countries.
What is the effect of POPs
POPs are highly toxic and exposure can take place through diet, environmental exposure, or accidents. They negatively affect humans, plant and animal species and natural ecosystems both in close proximity and at significant distances away from the original source of discharge.
Exposure to POPs in humans can cause several negative health effects including:
- Death
- Cancers
- Allergies
- Hypersensitivity
- Developmental changes
- Damage to the central and peripheral nervous systems
- Disruption of the endocrine, reproductive, and immune systems
- Diabetes, A study published in 2006 suggests that an increased level of POP.s in human blood serum can be linked to Diabetes (Lee et al 2006).
