Read the passage “Air pollution could be disrupting your sleep” and answer the questions. Air pollution could be disrupting your sleep Global warming keeping you up at night? Scientists say that could literally be the case. Researchers found people who live in areas with elevated levels of carbon dioxide often experience disrupted sleep over time. A sampling of about 2,000 people showed those who slept in areas with the highest levels of traffic-related carbon dioxide had a nearly 60 percent increased likelihood of having low sleep efficiency, or the percentage of time spent sleeping versus lying awake in bed. Those who slept in areas with the highest levels of small particulates had a 50 percent increased risk of disrupted sleep. “These new findings indicate the possibility that commonly experienced levels of air pollution not only affect heart and lung disease, but also sleep quality,” said lead author Martha E. Billings, an assistant professor of medicine at the University of Washington. “Improving air quality may be one way to enhance sleep health and perhaps reduce health disparities.” The study, presented at the American Thoracic Society’s International Conference, measured participants’ sleep and wake patterns over seven days and compared it to air pollution estimates at each person’s house. Billings said air pollutants can lead to irritation and inflammation in airways and nasal passages. Pollution, she added, could affect the bloodstream, which could impact the regulation of breathing and sleep. Pollution, the study said, has been tied to asthma, chronic obstructive pulmonary disease (COPD), lower respiratory infections and even sleep apnea. On the other hand, researchers said pollution may actually improve sleep. Researchers added more studies need to be done on how other pollutants affect sleep. The study’s results don’t bode well for tired inhabitants of Earth. In 2016, scientists found the world’s carbon dioxide levels were the highest they’d been in millions of years. Question 1: What might the commonly experienced levels of air pollution probably affect? Answer: It affects people’s __________ as well as their heart and lung disease.