Answer four of the following questions. Answers should be ~150 words. Use APA 7t

Answer four of the following questions. Answers should be ~150 words. Use APA 7th edition. Academic sources shall be used. 
Describe the design of a landfill disposal site. What microbial and physical processes take place in a landfill? How do modern landfills protect the environment from toxic chemicals? 
What historical observation led to the fluoridation of water? Take a position for or against the fluoridation of water. 
What are two of the most common occupational illnesses today (as opposed to injuries) found in private industry? What are the causal factors for these conditions? 
The number of occupational illnesses has been on the decline in the last few decades. What factors have led to this decline? What steps can be taken to reduce occupational hazards and thereby improve the health of workers? 
Name some of the portals of entry into the human body for toxic metals. Describe the methods by which these toxic metals may access specific portals of entry. What precautions can be taken to help prevent exposure to heavy metals?
Discuss some (3) of the distinct ways in which agriculture contributes to climate change? What can be done to address each of these things. 
Discuss why the water used to flush toilets and other waste is potable water. 
Extra credit: What is environmental health and what is its purpose?