Study of Lung Health Among Workers Exposed to Diesel Exhaust

Background: \- Diesel fuel is the most commonly used fuel to power cars and trucks worldwide. However, diesel exhaust fumes can have harmful effects on the body. Researchers are interested in studying how diesel exhaust exposure can affect lung health. To study these effects, researchers will look at employees of a diesel truck engine testing facility in China. Some workers at this facility are exposed to high levels of diesel exhaust. This study will compare tests and monitoring information from a group of highly exposed workers and a similar group of unexposed comparable controls. Objectives: * To study the effects of diesel exhaust on lung health. Eligibility: * Participants will be drawn from a diesel truck engine testing facility and other workplaces in China. * Individuals at least 18 years of age who work in workshops with diesel fuel. * Individuals at least 18 years of age who work in workshops that do not use diesel fuel. Design: * Depending on what type of factory study subjects work in, participants will wear personal air pumps and small badges on their clothing on one or more days. This equipment will measure particles, chemicals, and other compounds in the air. This information plus other information collected in the study including workplace practices will be used to estimate exposure to diesel exhaust among study subjects. * Participants will provide a number of study samples. These samples include blood, urine, and sputum. To collect other samples, participants will also have a mouth rinse, cheek cell scrapes, and nasal cell scrapes. They will also have a physical exam. * Treatment will not be provided as part of this study. Participants will receive financial compensation for participation in the study.