(Español Naphthalene is a type of polycyclic aromatic hydrocarbon (PAH) and possible carcinogen. It is found abundantly in outdoor air with traffic being the largest source. Elevated levels of naphthalene are also found in indoor air when mothballs or kitchen stoves burning biomass fuels are used.

Naphthalene is derived from petroleum and biofuel products and is found entirely in a gaseous phase rather than as a particulate. Human exposure to naphthalene is primarily through inhalation, although it can be ingested and absorbed through the skin. Due to the volatile nature of naphthalene, a box of mothballs can elevate indoor naphthalene levels to levels compatible with mid to upper level occupational exposure, with higher concentrations in smaller apartments or enclosed areas.

A cause of concern is that some Caribbean immigrant families in New York City frequently use mothballs as air fresheners. Therefore understanding potential downstream effects of naphthalene exposure has become increasingly relevant. The Center is currently conducting studies of the effects of naphthalene in the New York City cohort; the data collection and analysis is still ongoing.