Personal Sampling for Air Contaminants

Exposures to substances with exceptionaily high PELs (Permi.ssible Exposure Limits) in relatively dust-free atmospheres, e.g., ferric oxide and aluminum oxide. Intermittent processes with substances without STELs (Short Term Exposure Limits), 

The objective of a proper sampling program is to take a sufficient number of samples to obtain a representative estimate of exposure. Contaminant concentrations vary seasonally, with weather, with production levels, and in a single location or Job class. The number of samples taken depends on the error of measurement and differences in results. It is important also that if the employer has conducted air sampling and monitoring in the past, a thorough review of the records should be made. 

Bulk Samples are often required to assist the laboratory in the proper analysis of field samples. 

Screen the sampling area using detector tubes, if appropriate. Determine the appropriate sampling technique. Prepare and calibrate the equipment and prepare the filter media. 

Select the employee to be sampled and discuss the purpose of the sampling. Inform the employee when and where the equipment will be removed. Stress the importance of not removing or tampering with the sampling equipment. Turn off or remove sampling pumps before an employee leaves a potentially contaminated area (such as when he/she goes to lunch or on a break). 

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Occupational Health and Safety Administration Technical Manual, Section 1- Sampling, Measurement Methods, and Instruments, Chapter 1 -Personal Sampling for Air Contaminants, Appendix 1 1-6. Sampling and Analytical Errors (SAEs) (Issued by OSHA Instruction TED 1.15, September 22, 1995 amended by OSHA Instmction TED 1.15 CH-1, May 24,1996). 

Occnpational Health and Safety Administration Technical Manual, Section I- Sampling, Measurement Methods, and Instruments, Chapter 1 - Personal Sampling for Air Contaminants,... 

A personal sampling method for common organophosphate additives in hydraulic fluids in occupational air was developed with the aim of exposure assessment in working atmospheres potentially contaminated by hydraulic fluids, simultaneously collecting both the aerosols and the vapours. The described sampler combined a glass fibre filter with a Chromosorb 106 adsorbent tube. Desorption was performed with dichloromethane for GC/MS analysis (Solbu et al. 2007). 

Personal air sampling is preferred over area sampling for evaluating worker exposure to contaminants in workplace air. The worker wears a sampling device that is placed very close to the breathing zone to collect an air sample. Area air samples are normally used to evaluate background concentrations and locate sources of exposures. The sampling device is placed in a fixed location in the area of interest. 

The contractor at Site H had established area and personnel sampling consistent with HAZWOPER requirements. A photo ionization detector (PID) and a real-time aerosol monitor (RAM) were used on a daily basis to screen for potentially hazardous levels of contaminants. On a weekly basis, personal air samples were collected and submitted for laboratory analysis. PPE requirements, however, were often not based on this data because the oversight agency had established inflexible minimum PPE requirements. The audit team found many of the PPE requirements on Site H to be excessive in light of site monitoring data and hazard determinations. 

Right now, we have to deal with incubation time and wait for victims to develop symptoms. The incubation time for anthrax is one to six days. In this example, anthrax victims would have one to six days between exposure and the onset of symptoms. Anthrax is not transmissible from person to person. Compare this to the incubation time with that of the virus, smallpox, which is ten to seventeen days. Smallpox is highly transmissible from person to person. After exposure to smallpox, a person could travel by air around the world a number of times and contaminate many people before developing any symptoms. However, naturally occurring smallpox has been eradicated worldwide since 1977. Terrorism could rapidly change that eradication to an attack since samples of the smallpox virus have been stored in both the United States and Russia. 

In this chapter, the use of gas chromatography-mass spectrometry (GC-MS) in the field of occupational and environmental health is discussed with emphasis on the detection of traces of nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) from complex source emissions (diesel engine exhaust) in the ambient atmosphere and in personal air samples (workplace atmosphere). The uptake, and distribution, covalent binding to proteins, and excretion of urinary metabolites are addressed in terms of specific MS-applications. The analysis of drinking water and foodstuffs for contaminants or residues is not discussed these topics are presented elsewhere in this book. 

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