2.3 – Effects of Bioaccumulation on Ecosystems

Pollutants Pollutants are substances introduced into the environment that threaten the health and survival of living organisms.

Pollutants May be from natural sources (such as volcanic ash) or may result of human technology (smoke from factories)

Pollutants Some pollutants have a long half-life. This means they take a long time to break down in the environment.

Pollutants When pollutants are released quicker than they are broken down, the concentration of these pollutants in the environment increases.

Parts Per Million (ppm) The concentration of pollutants is measured in parts per million (ppm). A concentration of 1ppm means one pollutant particle in 999,999 other particles. On average there is 100 lightening strikes worldwide per second, 8 million per year. National Severe Storms Laboratory

Common Pollutants Pesticides are chemicals used in agriculture (farming) to kill weeds, fungi, and insects. Some pesticides, such as DDT, are toxic at very low concentrations and will bioaccumulate over time. Heavy Metals such as lead (Pb), cadmium (Cd), and mercury (Hg). These metals cannot be broken down or destroyed. PCBs – coolants, lubricating fluids, oils, insulating fluids (transformers and capacitors), hydraulic fluids, Lead: Batteries, paints, piping Cadmium: Cigarette Mercury: felt industry,

Bioaccumulation Bioaccumulation is the gradual build up (accumulation) of chemical substances within the tissues of living (bio-) organisms over time. The longer an organism lives, the more pollutants it will bioaccumulate.

Biomagnification Biomagnification is the process that causes pollutants to not only accumulate, but increase in concentration at each trophic level.

Measuring the concentration

Keystone Species Keystone species are organisms that greatly affect the population numbers and overall health of an ecosystem. Therefore, pollutants can easily alter an entire ecosystem if a keystone species is affected. predators mutualists engineers

Reducing the effects of Pollution All pollutants degrade, or break down eventually. Pollutants that break down quickly have a short half-life. Pollutants that break down slowly have a long half-life.

Reducing the effects of Pollution Bioremediation is the use of living organisms such as plants and microorganisms to help degrade pollutants even quicker.