Complex sentence: The subjects of the study were overweight Latin (x) children, between the ages of eight and fifteen, residing in areas with elevated particulate matter and nitrogen dioxide levels, air pollutants caused nearby power plants and high-volume vehicle traffic.
Split into simpler sentences: The subjects of the study were overweight Latin (x) children, between the ages of eight and fifteen, residing in areas with excess particulate matter. In particular, the neighborhoods of the children were located in areas of elevated nitrogen dioxide levels, an air pollutant caused nearby power plants and high-volume vehicle traffic.