Why are pollutants measured in ppm

Sustained yields are most commonly applied to forestry and fishing activities and limit short-term harvests to allow for longer-term regeneration of resources from the remaining parent View Full Term.

By clicking sign up, you agree to receive emails from Safeopedia and agree to our Terms of Use and Privacy Policy. Parts per million PPM is a unit of measurement used when expressing a very dilute concentration level of pollutants in the air, water and other fluids. For example, 1 PPM of ink in water means that in a million mass units of water there would be one mass unit of ink.

Thus, PPM refers to one item in a million of anything of the same size. PPM is commonly used in measuring air, water and body fluids pollution.

PPM is the mass ratio between a component and a solution. Mathematically, 1 PPM can be expressed as following:. Subscribe to the Safeopedia newsletter to stay on top of current industry trends and up-to-date know-how from subject matter authorities. Air pollutant units and conversion factors Air pollutants are measured in various units. Page last updated 6 November The following buttons will open a feedback form below Was this page helpful? Yes No. Thank you for your feedback.

Would you like to tell us more? Your comments required Tell us what you liked about the page or how it could be improved. I would like EES to contact me in the future for help improving services and to share information about national parks or other environmental activities. Primary standards provide public health protection, including protecting the health of "sensitive" populations such as asthmatics, children, and the elderly.

Secondary standards provide public welfare protection, including protection against decreased visibility and damage to animals, crops, vegetation, and buildings. Periodically, the standards are reviewed and sometimes may be revised, establishing new standards.

The most recently established standards are listed below. In some areas of the U. It is shown here in terms of ppb for the purposes of clearer comparison to the 1-hour standard level. The previous O 3 standards are not revoked and remain in effect for designated areas. Additionally, some areas may have certain continuing implementation obligations under the prior revoked 1-hour and 8-hour O 3 standards.

The Menu of Control Measures MCM provides state, local and tribal air agencies with the existing emission reduction measures as well as relevant information concerning the efficiency and cost effectiveness of the measures.