Article Abstract:
Inhalation toxicologists are studying atmospheric ultrafine particles, which have a diameter of less than 0.1 micrometer, to discover whether they are hazardous to public health. Toxicologists are examining the chemical composition of atmospheric ultrafine particles, the number of concentration and size distribution, under the wintertime conditions in Pasadena, CA. The experiments are conducted with the use of a scanning differential mobility analyzer, a laser optical counter and two micro-orifice impactors. Toxicologists believe that the biggest contributors to the concentration of ultrafine particles are organic compounds.
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Article Abstract:
The elements present in petroleum refineries' zeolite cracking catalysts were studied. Neutron-capture prompt gamma-ray activation analysis and instrumental neutron activation analysis were used to analyze 10 fluidized catalytic cracker (FCC) zeolites for 38 elements. The 10 FCC catalysts had different compositions, but all exhibited highly enriched light rare earth elements. The emissions from refineries and oil-fired coal plants could be identified through the ratio of lanthanum to vanadium.
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Article Abstract:
Airborne particulate mercury experiments in the New York State area reveal that approximately 55% of airborne mercury originates from Ontario and Quebec smelters while only 25% originates from the US. Instrumental Neutron Activation Analysis was used to determine airborne mercury levels at five remote NY sites and results also suggest that the drop in Hg levels from February 1993 may be attributed to reduced emissions from Canadian smelters.
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