Wednesday, February 1, 2012

hydrogen sulfide exposure

The World Health Organization (WHO 1981) advises ambient concentration levels of hydrogen sulfide "should not exceed 5 ppb, with a 30-minute averaging time.”

Neurophysicological abnormalities have been reported in studies of residents living along the fenceline of crude oil processing plant which exposed residents to hydrogen sulfide at 10 parts per billion.  Other studies show the adverse health effects reported by residents in areas of annual exposure levels of hydrogen sulfide between 7 and 27 ppb. The adverse health effects reported by residents include “central nervous systems, ear/nose/throat, respiratory, muscle/bone, skin, immune, cardiovascular, digestive, teeth/gums, urinary, blood” .

In St. Bernard Parish, the community air monitors have demonstrated exposure to hydrogen sulfide at or above an hourly average of 10 ppb and daily exposures above 1 ppb.  Residents do not have access to the annual exposure levels nor the peak five minute and 30 minute exposure levels which comprise the hourly averages displayed on the monitors.  An EPA toxicological review infers a daily exposure to H2S withouth risk to be 1.4 ppb or 0.0014 ppm. {page 52 of EPA report}.

Some peak hourly readings of Hydrogen Sulfide
1- 16 ppb of H2S on 9/26/2011 and 11 ppb of H2S on 1/04/2012 at LDEQ’s Ch_Vista ambient air monitor, located at Bluebird Park in the Chalmette Vista neighborhood of Chalmette.  This neighborhood is adjacent to ExxonMobil's Chalmette refinery and Rain CII Carbon's petroleum coke plant.

2- 24 ppb of H2S on 1/30/2012 at Valero Refining‘s Meraux plant's community air monitor on Ventura Drive in Chalmette. The Ventura Drive monitor is located in the Floral Estates neighborhood in Chalmette, adjacent to the Valero Meraux plant.

3- 16 ppb of H2S on 2/10/2010 at LDEQ’s Meraux monitor, located at Joe Davies Elementary School playground in Meraux. The Meraux site recorded a spike in H2S on the afternoon of February 10, 2010 during the time of a startup at the former Murphy Oil Meraux refinery. (now owned by Valero).

4- 26 ppb, 20 ppb, 44 ppb, and 33 ppb of H2S on Feb 16th, 18th, 19th and 20th respectively in 2010 at LDEQ's Meraux monitor.  On February 21, 2010 the former Murphy Oil refinery (now owned by Valero) reported it had discovered it was sending elevated levels of hydrogen sulfide to the flares.  {page 20 of report at this link}.  During the same time, the refinery reported permit exceedances for both flares.

5 -   58 ppb of H2S at Chalmette High School.  The LDEQ’s Chal_High community air monitor, formerly located at our only high school, recorded H2S readings as high as 58 ppb.    click here for link to report   The LDEQ dismantled the Chalmette High School monitor site just prior to the 2011 installation of Valero's Ventura Drive site in Chalmette. 

6-  91 ppb of H2S at Lower Algiers school site.  The LDEQ report in the above link also documents another former school site; this one is in Lower Algiers (across the river from the ExxonMobil Chalmette refinery and Rain CII Carbon petroleum coke plant) where the LDEQ monitor recorded H2S readings as high as 91 ppb . This Lower Algiers monitoring station was known as Entergy and was dismantled in 2008 in preparation for Hurricane Gustav.  It was never restored.   Lower Algiers, like St. Bernard Parish, is an under-served, economically disadvantaged  community.  

7-  114 ppb at LDEQ's Ch_Vista site noted in the same report.
The Chalmette Vista ambient air monitoring data is accessible at this link, under site data, select CH_VISTA.

The Meraux ambient air monitoring data is accessible at the above link, under site data, select Meraux.

The Valero Refinery community air monitor commenced in August 2011. The data is accessible at this link for the Ventura Drive monitor in Chalmette, select hourly readings.

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