Los Angeles County interim health officer, Dr. Jeffrey Gunzenhauser is acting reckless and seems clueless with the Air Quality Management District’s air monitoring evaluations of hexavalent chromium (Cr(VI)) in Los Angeles County by blaming a single industry for the problem.
Dr. Gunzenhauser recently noted,
“Based on recent evaluations of hexavalent chromium [also known as chromium 6] documented by [the South Coast Air Quality Management District’s] extensive monitoring network, Public Health has determined action is needed without delay to protect the health of the Paramount community.”
The problem with Dr. Gunzenhauser’s statement is that the Air Quality Management District has repeatedly admitted that the air monitors are inconclusive and it admits in numerous communications the impossibility of accurately attributing the hexavalent chromium to a particular source.
The AQMD director Wayne Nastri wrote to Governor Jerry Brown and the members of the California State Legislature that:
“To really benefit disadvantaged communities, diesel emissions must be drastically reduced. In South Coast and San Joaquin Valley, over 80% of NOx emissions contributing to ozone and PM2.5, and about 90% of the basin-wide risk from air toxics, come from mobile sources, (70% from diesel particulates).” (AQMD Letter to Jerry Brown 7-12-17)
In a recent town hall meeting in Compton, AQMD assistant deputy executive officer of the monitoring and analysis division for science & technology advancement, Dr. Jason Low, talked about the air monitoring in Paramount and Compton and answered why there were spikes in chromium 6 readings during the weekends and holidays, the machine shops were closed:
“So towards the end of the presentation I expressed some of the challenges associated with air monitoring and as Mr. Nastri pointed out our team is looking at other potential sources. We take obviously looking at the operational data for facilities, but I also mentioned we are looking at other non-facility sources such as road construction, such as other facts that we can look at winds to determine if there is other locations that these elevated levels are coming from. So we are not just looking at the facility approach, but potentially other sources.” (Town Hall Meeting Video)
Health-based hexavalent chromium guidance values have been developed for residential exposures by the Agency for Toxic Substance and Disease Registry and the Office of Environmental Health Hazard Assessment of the California EPA
The Agency for Toxic Substances and Disease Registry (ATSDR), which is part of the Centers for Disease Control, has set a minimal risk level (MRL) for long-term continuous exposure to Cr(VI) at 300 ng/m3.
The Office of Environmental Health Hazard Assessment (OEHHA) of the California EPA set a reference exposure level (RSL) to Cr(VI) at 200 ng/m3.
In the AQMD’s monitoring of hexavalent chromium, the measured levels have never come close to these health-based values. The monitors show hexavalent chromium at less than 1 ng/m3 on average during the past several months in Paramount and Compton. Review the numbers for yourself:
AQMD Paramount Readings:
AQMD Compton Readings:
The biggest concern is that Dr. Jeffrey Gunzenhauser is being guided by a desire for a particular outcome, while conveniently making sure that science takes a backseat. The residents of these cities deserve that the Los Angeles County of Public Health conduct their AQMD air monitoring evaluation based on sound science, not personal agendas.
