1- Describe how lethal does (LD) levels and effective does (ED) levels are used to assess the positive and negative impacts of chemicals. Describe how safe exposures and safe dosages are assessed.
2- (i) Describe the potential negative impacts on a small river downstream from where it receives a dairy products factory liquid waste discharge that has a high biological oxygen demand (BOD).
(ii) Describe how soils contaminated by heavy metals can be decontaminated with living plants.
3- (i) what are the main sources for anthropogenic sulphur dioxide (SO2) emissions that can create acid rain? Describe the impacts that acid rain can have on forest and lake ecosystems, as well as buildings and other constructed structures.
(ii) what problems can nitrogen oxides emitted from burning fossil fuels cause in the environment?
4- what is the significance of the individual factors used to assess the Air Quality Index (AQI)? Describe the how the AQI is determined and used.
5- (i) why is the ozone layer important to human health and wellbeing? Describe how anthropogenic chemicals can destroy the ozone layer.
(ii) Describe how petrochemical smog is created, including the conditions needed for its formation, and the potential health impacts that can occur as a result of its occurrence.
For each of the above 5 questions describe, discuss and add to the answers (diagram or figure or tables where appropriate and needed.)