Which of the following environmental factors can contribute to decreased lung function?

Air pollution is a significant factor that can lead to decreased lung function. It encompasses various harmful substances present in the air, including particulate matter, ground-level ozone, carbon monoxide, sulfur dioxide, and nitrogen oxides. These pollutants can irritate the airways, cause inflammation, and exacerbate existing respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD). Long-term exposure to air pollution is linked to a decline in lung function and can aggravate respiratory illnesses, leading to more severe health issues.

In contrast, while sunlight exposure may have various effects on health, it is not directly connected to decreased lung function. High humidity levels can influence breathing comfort but do not typically cause long-term lung function decline. Similarly, while cold temperatures can make breathing feel more difficult for some individuals, especially those with respiratory conditions, they do not primarily contribute to a permanent reduction in lung function like air pollution does. Thus, air pollution stands out as a critical environmental factor negatively impacting respiratory health.