Which of the following is a major class of air pollutants?

What was the estimated number of premature deaths caused by outdoor air pollution worldwide in 2012?

In which regions of WHO did the greatest number of premature deaths due to outdoor air pollution occur?

How many people die annually from illnesses related to household air pollution from cooking with solid fuels?

What is the leading cause of premature deaths for children under 5 due to household air pollution?

Which is the most common indoor air pollutant?

What is a common source of nitrogen oxides in indoor air?

What are the primary greenhouse gases in Earth's atmosphere?

What is one effect of ozone depletion?

What are some of the health effects of higher levels of UV radiation?

What are some of the potential ecological impacts of ozone depletion?

What causes acid deposition?

What are the effects of acidic rain deposition on lakes and rivers?

What are the long-term effects of acid deposition?

Where is an example of forest decline caused by acid deposition?

How many people worldwide lack access to adequate clean water?

Which of the following is a source of water pollution caused by human activity?

What type of pollution is caused by fertilizers and pesticides?

Which of the following is a potential source of heavy metal pollution in water?

Which of the following is an example of a direct source of water pollution?

What are nonpoint sources of water pollution?