Human health risk characterization of petroleum coke calcining facility emissions

Assessment of the health risk related to exposure to ultrafine, fine, and total particulates and metals in a metal finishing plant

The materials and byproducts of the processes used in the metal finishing industry are released as particle contaminants into the air in the workplace. The present study aimed to determine the concentrations and size distributions of these particles and of elements chromium, nickel, copper, manganese, cobalt, and lead (Cr, Ni, Cu, Mn, Co, and Pb, respectively) in a metal finishing industry and evaluate their potential health risks. Particles that are airborne from the dipping baths in the plant were sampled using a Sioutas cascade impactor at five different size fractions (PM_>2.5, PM_1.0-2.5, PM_0.5-1.0, PM_0.25-0.5, PM_<0.25) and gravimetric analyses were conducted on the sampled filters. The GF-AAS 600 graphite atomic absorption spectrophotometer (PerkinElmer Corporation, Waltham, MA, USA) was used to analyze the elements and the method of USEPA was used to assess the health risk. The ratio of fine particles (PM_2.5) to total suspended particles (TSPs) was 0.6. We observed that 50% of TSPs were composed of PM_1.0 and that 68-88% of the metals were found in the fine particle fractions. Pb, Cr, and Mn were significantly positively correlated in the PM_1.0 fraction, and the highest linear relationship was found between Pb and Cr (r = 0.85, p < 0.01). The total hazard quotient (HQ) for PM_2.5 was 1.43, which is higher than the acceptable limit of 1.0. The excess lifetime cancer risk (ELCR) for hexavalent chromium (Cr[VI]) in PM_2.5 was 6.09 × 10^-5 for female workers and 6.54 × 10^-5 for male workers, which are higher than the acceptable limit of 1.0 × 10^-6, while total ELCRs for female and male workers were 6.21 × 10^-5 and 6.21 × 10^-5, respectively. The lifetime cancer risk associated with Cr(VI) in Cr electroplating plants should be taken into consideration as a significant health risk for the workers.

A case study of potential human health impacts from petroleum coke transfer facilities

Petroleum coke or "petcoke" is a solid material created during petroleum refinement and is distributed via transfer facilities that may be located in densely populated areas. The health impacts from petcoke exposure to residents living in proximity to such facilities were evaluated for a petcoke transfer facilities located in Chicago, Illinois. Site-specific, margin of safety (MOS) and margin of exposure (MOE) analyses were conducted using estimated airborne and dermal exposures. The exposure assessment was based on a combined measurement and modeling program that included multiyear on-site air monitoring, air dispersion modeling, and analyses of soil and surfaces in residential areas adjacent to two petcoke transfer facilities located in industrial areas. Airborne particulate matter less than 10 microns (PM₁₀) were used as a marker for petcoke. Based on daily fence line monitoring, the average daily PM₁₀ concentration at the KCBX Terminals measured on-site was 32 μg/m³, with 89% of 24-hr average PM₁₀ concentrations below 50 μg/m³ and 99% below 100 μg/m³. A dispersion model estimated that the emission sources at the KCBX Terminals produced peak PM₁₀ levels attributed to the petcoke facility at the most highly impacted residence of 11 μg/m³ on an annual average basis and 54 μg/m³ on 24-hr average basis. Chemical indicators of petcoke in soil and surface samples collected from residential neighborhoods adjacent to the facilities were equivalent to levels in corresponding samples collected at reference locations elsewhere in Chicago, a finding that is consistent with limited potential for off-site exposure indicated by the fence line monitoring and air dispersion modeling. The MOE based upon dispersion model estimates ranged from 800 to 900 for potential inhalation, the primary route of concern for particulate matter. This indicates a low likelihood of adverse health effects in the surrounding community. Implications: Handling of petroleum coke at bulk material transfer facilities has been identified as a concern for the public health of surrounding populations. The current assessment, based on measurements and modeling of two facilities located in a densely populated urban area, indicates that petcoke transport and accumulation in off-site locations is minimal. In addition, estimated human exposures, if any, are well below levels that could be anticipated to produce adverse health effects in the general population.