hajapäästölähteet

Hajapäästölähteet, also known as diffuse pollution sources, refer to pollution that originates from widespread areas rather than a single, identifiable point. Unlike point source pollution, which can be traced to a specific outlet like a factory smokestack or a sewage pipe, diffuse pollution comes from numerous, often mobile sources spread across a landscape.

Common examples of hajapäästölähteet in urban environments include stormwater runoff from streets, parking lots, and rooftops. This runoff can pick up pollutants such as oil, grease, heavy metals, and litter from surfaces and carry them into waterways. Agricultural activities are a significant source of diffuse pollution in rural areas. Fertilizers, pesticides, and animal waste can be washed off fields by rain and irrigation, contaminating rivers, lakes, and groundwater.

Other diffuse sources include atmospheric deposition, where pollutants emitted into the air settle onto land and water, and leakage from septic systems or underground storage tanks that are not easily localized. The cumulative effect of these widespread, low-concentration sources can be substantial and pose a significant threat to water quality, ecosystem health, and human health. Managing hajapäästölähteet often requires a landscape-level approach, focusing on best management practices across broad areas rather than targeting individual polluters.