Given the multitude of potential Pb sources and pathways of exposure, it is often difficult to distinguish the proportion of PbB attributed to air-related pathways those pathways where Pb passes through ambient air from a source to human exposure.
Atmosphere-supplying respirators, such as the self-contained breathing apparatus (supplies air from a source such as a tank carried by the user), and the airline respirator (uses air supplied via a hose from a distant source), provide air from an independent source as opposed to purifying ambient air.
He has not spent a great deal of time in Albany, the epicenter of his troubles, availing himself of the state-owned air fleet — a source and symbol of geographic freedom and power (and of its occasional abuses).
The jets would be used in a reconnaissance role to help transport planes deliver aid supplies and not for air strikes, a source told BBC defence correspondent Jonathan Beale.
The development of the respiratory system represents an evolutionary hallmark that allowed vertebrates to survive on land utilizing air as a source of oxygen.
One needs fuel, air, and a source of combustion for fire to be successfully made.
Point sources in air (A), point sources in water with no background concentration (B), point sources in water with 0.1% background concentration (C), and point sources in water with 1% background concentration (D).
In flames of CH4 and air, a substantial source of N2O comes from the reverse of the reaction N2O + CH3 → CH3O + N2 in the reaction zone.
NewsGang combines a phone conference call with video from my MacBook Air, an open source free video switching tool called CamTwist, and another open source audio switching tool called Soundflower to create the video stream.
However, exposure studies have identified indoor air as the main source of exposure to many air pollutants and a source of some of the highest noncancer and cancer risks (U.S. Environmental Protection Agency 1990; Wallace et al. 1987).
Once, her mother said, the couple was stuck in the air for hours, a source of great anxiety for Ms. Barton.
