Area measurement (square measure) used primarily in the United States. One (1) acre is equal to 43,560 square feet, 4,046.86 square meters, or 0.4047 hectares.

Harmful biological effects that occur following a single or multiple rapid exposures to or doses of a noxious compound or substance

The activities, operations, or purposes that are employed in a particualr geographic area; the specific manner in which a parcel or tract of land is utilized. Land use is usually regulated by municipal governments through zoning ordinances, although some land uses are regulated by state or federal governments.