Presentation on theme: "Effects of Pesticides Discuss the effects continually introducing new pesticides into the environment."— Presentation transcript:
1 Effects of PesticidesDiscuss the effects continually introducing new pesticides into the environment
2 Pesticides All pesticides are toxic to some living thing Herbicides FungicidesInsecticidesSynthetic pesticides are lab made and generally take longer to break down. Due to this they can accumulate in the environment. Natural pesticides tend to break down quicker, and are less harmful to the environment.
3 Effects on non-target species Pesticides have direct or indirect effects on other living things. They do so by;Changing food websDirect or indirect poisoningChemical biomagnification andhabitat changes.
4 Bioaccumulation Accumulation of chemicals in the tissue of organisms “an increase in the concentration of a chemical in an organism over time compared to the chemicals conc in the environment.”Is the net result of a chemicalsUptake…….storage…….elimination
5 Biomagnification Is the increase in concentration of a bio-accumulated chemical as it movesthrough the food web
8 Example of biomagnification the Bald Eagle was severely affected in the mid-20th century by a variety of factors, among them thinning of egg shells, attributed to the use of the pesticide DDT. Bald Eagles, like many birds of prey, were especially affected by DDT due to biomagnification. DDT itself was not lethal to the adult bird, but it interfered with the bird's calcium metabolism, making the bird either sterile or unable to lay healthy eggs. Female eagles laid eggs that were too brittle to withstand the weight of a brooding adult, making it nearly impossible to produce young.
9 Effects on humans Prolonged exposure to pesticides in humans can lead Dangers of pesticide use. WWF Australia You TubeProlonged exposure to pesticides in humans can leadto severe disorders in our reproductive, nervous andimmune system, also been linked to cancer.IncludeAsthmaSkin conditionsBirth defectsNeurological effectsCancerHormone disruptionetc
10 DDTDichlorodiphenyltrichloroethane (DDT) was first synthesised in 1874 but its power as an insecticide was not reported until 1939
11 DDTIt is a cheap chemical, highly toxic to insects but with extremely low toxicity to mammals and humans. Was widely used during the 1950s to treat crops