As noted above, there are many sources of lead in the environment, including drinking water, food, emissions from gasoline combustion, industrial air emissions, and of course paint coatings. Although the principal route of exposure for people in the general population is through food, the most common route of exposure in the construction industry may equally be through ingestion and inhalation. It is interesting to also note, that sources of lead that produce excess exposure and toxic effects are usually environmental and presumably controllable.