Question

1. explain why indoor air for a long time was generally ignored.
2. what eventually brought the attention of indoor air to many health experts?
3. compare the amount of human exposure to indoor and outdoor air pollution today.
4. why are the levels of indoor air pollutants of particular concern?
5. explain how our need to conserve energy has led to greater indoor air pollution.
6. identify the people who are most susceptible to indoor air pollution and why.

Explanation:

1. Explanation for long - time ignorance: There was a lack of awareness about indoor air pollutants and their impacts. Also, outdoor air pollution was more visible and received more attention.
2. What brought attention: Health problems associated with indoor environments, such as sick - building syndrome, and studies linking indoor air quality to human health.
3. Comparison of exposure: People spend a significant amount of time indoors (up to 90% according to some studies), so exposure to indoor air pollution can be high. While outdoor air pollution is a concern, the cumulative exposure indoors can be substantial due to the time spent.
4. Concern for indoor pollutants: Indoor pollutants can be more concentrated as the air volume in an indoor space is limited compared to the outdoors. Also, some indoor pollutants like formaldehyde from furniture and VOCs from cleaning products can have long - term health effects.
5. Energy conservation and pollution: To conserve energy, buildings are made more air - tight, reducing natural ventilation. This traps pollutants inside, leading to higher indoor air pollution levels.
6. Susceptible people: The elderly, children, and those with pre - existing respiratory or cardiovascular diseases are more susceptible. Their immune systems may be weaker or their respiratory systems more sensitive.

Answer:

1. Lack of awareness and more focus on outdoor pollution.
2. Health problems and related studies.
3. High indoor time leads to significant indoor exposure; outdoor pollution is also a concern but cumulative indoor exposure can be high.
4. Higher concentration due to limited space and long - term health effects of pollutants.
5. Air - tight buildings reduce ventilation, trapping pollutants.
6. Elderly, children, and those with pre - existing diseases due to weaker immune or more sensitive respiratory systems.