Pretend you are a teacher preparing a quiz for the text I will provide. 
            Each quiz question should follow the format below. 
            Ensure that you carefully recheck the questions and answers for accuracy. 
            The output should be a ready-to-use list of dictionaries for the Python eval function:

            [

                    "question": "WRITE THE QUESTION HERE",
                    "options": ["A) OPTION_1", "B) OPTION_2", "C) OPTION_3", "D) OPTION_4"],
                    "answer": INDEX_OF_CORRECT_ANSWER_IN_OPTIONS_LIST,
                    "explanation": "EXPLAIN WHY THE ANSWER IS CORRECT"

            ]

            Text:
            A., Meng, Q., & Kaden, D. A. (Eds.). (2022). Risk 
assessment for environmental health. CRC Press. 
 
 
 
 
14 
 
 
 
CHAPTER TWO 
 
Air, water and food 
 
Outlines 
• Air quality and health 
Importance of air for human life  
Air pollution 
• Water quality and health 
Characteristics of safe water 
water pollution 
• Safe food supply 
Characteristics of healthy foods 
Sources for food contamination 
Five keys to safer food preparation  
 
 
 
  
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Aspects of Environmental Health 
1- Air Quality and Health: 
Air is a mechanical mixture of gases. The normal composition of external air 
by volume is approximately as follows: Nitrogen - 78.1 percent; Oxygen - 20.93 
percent; Carbon dioxide - 0.03 percent. The balance is made up of other gases (.94%) 
that occur in traces, e.g., argon, neon, krypton, xenon and helium. In addition to these 
gases, air also contains water vapor, traces of ammonia and suspended matter such 
as dust, bacteria, spores and vegetable debris. 
Importance of air for human life  
▪ Gas exchange that is vital for human life.  
▪ Helps in cooling of body as it allows heat loss from the body.  
▪ Transmit sense of hearing and smell. 
▪ Feeling of comfort and better performance of work. 
➢ Pollution of air by dust, smoke, toxic gases and chemical vapors has resulted in 
sickness and death. 
- Pollution: refers to the act of contaminating the environment to the extent that is 
negatively affects people health. 
- Air pollution: is the contamination of the air we breathe, indoors or outdoors, by 
any chemical, physical or biological agent that change the natural characteristics of 
the atmosphere.  
16 
 
 
 
 
- It is especially prevalent in highly industrialized and urban areas where 
concentrations of motor vehicles and factories produce large volumes of gaseous 
pollutants. 
- Studies have shown that air pollution effects on humans are a significant public 
health concern, not only because of their role in climate change, but also because 
exposure to air pollution can increase morbidity and mortality. Also studies reveals 
that air pollution affect lung development in children. 
According to the WHO, air pollution effects on humans are significant. For example, it 
causes: - 
• 29% of all global deaths from lung disease. 
• 24% of all global deaths from stroke. 
• 17 % of all global deaths and disease from acute lower respiratory infection. 
17 
 
 
 
- Classification of air pollution according to occasion of exposure: 
1. Outdoor Air pollution: the pollutant(s) is present in the atmosphere outside 
homes or workplace. 
2. Indoor Air Pollution: the pollutant(s) is present inside homes or workplace. 
Sources of outdoor air pollution: 
> Natural sources:  
Earthquakes, volcanic eruptions, windstorms, forest fires, formation of 
radioactive particles from gases such as radon and decomposition of plants 
and animals. 
> Human generated (man-made) pollutants: 
a) Mobile 
sources 
(automobiles): 
include 
different 
methods 


            Quiz: