An evaluation was carried out to investigate the suitability of polyvinyl chloride (PVC) internal capsules, housed within air sampling devices, for gravimetric analysis of airborne particles collected in workplaces. Experiments were carried out using blank PVC capsules and PVC capsules spiked with 0,1 - 4 mg of National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1648 (Urban Particulate Matter) and Arizona Road Dust (Air Cleaner Test Dust). The capsules were housed within plastic closed-face cassette samplers (CFCs). A method detection limit (MDL) of 0,075 mg per sample was estimated. Precision S at 0,5 - 4 mg per sample was 0,031 and the estimated bias was 0,058. Weight stability over 28 days was verified for both blanks and spiked capsules. Independent laboratory testing on blanks and field samples verified long-term weight stability as well as sampling and analysis precision and bias estimates. An overall precision estimate Ŝ of 0,059 was obtained. An accuracy measure of ±15,5% was found for the gravimetric method using PVC internal capsules.

Polychlorinated biphenyls (PCBs) are industrial chemicals used in various applications requiring chemical stabilityand have now become widely dispersed. Their characteristics of persistence, low water/higher lipid solubility, contribute to their ability to bioconcentrate and bioaccumulate. Traditionally PCBs have been regulated as food contaminants and the general population is primarily exposed by that route. PCBs in foodstuffs are generally higher chlorinated, resistant to metabolic breakdown, and elicit toxic changes that are thought to be predominantly receptor/parent PCB-driven. But for certain occupational exposures, and for those persons residing or working in contaminated buildings, and in large cities, an inhalation route of exposure may predominate. Airborne PCBs are, in contrast to foodborne PCBs, lower chlorinated, more volatile, and subject to metabolic attack. In this review, we have explored (geno-) toxic manifestations of PCBs typical of those found in air. Here metabolic conversion of the parent PCB to hydroxylated and other metabolic progeny appear to play a dominant role, especially in genotoxicity. We should be cognizant of the impact of exposures to airborne PCBs for those individuals who are occupationally exposed, for persons living near contaminated sites, for those who work or go to school in contaminated buildings, and especially cognizant of the young, the socio-economically disadvantaged and medically-underserved or nutritionally-deficient populations.

The (NMAM: www.cdc.gov/niosh/nmam) is a collection of methods for sampling and analysis of contaminants in workplace air (or surfaces) and in the blood and urine of workers who are occupationally exposed. NIOSH methods are used worldwide for occupational exposure assessment to chemical and biological agents. These methods have been developed or adapted by NIOSH and/or its partners and have been evaluated according to established experimental protocols and performance criteria. NMAM also includes associated chapters on quality assurance, sampling guidance, instrumentation, aerosol measurement, gas and vapor monitoring, portable monitoring devices, and so forth. Often NIOSH methods are developed in coordination with voluntary consensus standards organizations such as ASTM International, the Comité Européen de Normalisation (European Committee for Standardization, CEN) and the International Organization for Standardization (ISO). Efforts to harmonize NIOSH methods with relevant consensus standards procedures are of particular interest and are highlighted. NIOSH also has a formal Memorandum of Understanding (MOU) with the Institut für Arbeitsschutz der Deutschen Geseltzlichen Unfallversicherung (Institute for Occupational Safety and Health of the German Social Accident Insurances, IFA), whereby NIOSH is adopting selected IFA methods and vice-versa. An overview of recent research and technology transfer activities relating to NMAM methods is provided, with selected examples in applications to exposure science, notably workplace air monitoring. Included in the discussion are newly approved methods and those under development, as well as needs for new methods and updates. Of particular interest are recent NIOSH recommendations and associated research on air samplers used for sampling and analysis of airborne particles.