chronic exposure

coma and death can occur at exposure levels as low as 50 ppm--


Human Health Effects from Exposure to Low-Level Concentrations of Hydrogen Sulfide
EXPOSURE to high levels of hydrogen sulfide gas is a well-documented and understood hazard. OSHA and NIOSH standards have long recognized this acute risk with appropriate short-term maximum exposure levels for workers. However, long-term, chronic exposure to low levels of hydrogen sulfide is not as well understood.
To read the complete article, please go to:

http://ohsonline.com/articles/2007/10/human-health-effects-from-exposure-to-lowlevel-concentrations-of-hydrogen-sulfide.aspx

The article continues:

“Kilburn and Warshaw (1995) concluded neurophysiologic abnormalities were associated with average H2S concentration levels of 10 ppb with peaks of 100 ppb in a neighborhood of exposed residents.”

Remember, 10 ppb = 0.01 ppm

And

“EPA set the safe exposure level at 0.00014 ppm to protect sensitive people such as children and the elderly.”

The community air monitors at our only high school (known as Chal_High site) have recorded H2S readings as high as 58 ppb or 0.058 ppm.  click here for link to report which also documents a school site in Lower Algiers (across the river from the ExxonMobil Chalmette refinery) whose air monitor recorded H2S readings as high as 91 ppb or 0.091 ppm. This Lower Algiers monitoring station site is known as Entergy and was   dismantled in 2008 in preparation for Hurricane Gustav.  It was never restored. Lower Algiers is an under-served, economically disadvantaged neighborhood.

The Joe Davies school playground (known as the Meraux site) and the Bluebird Park neighborhood playground (known as the Chal_Vista site) also record hydrogen sulfide in ppb.

This morning, the Joe Davies school playground’s hydrogen sulfide exposure level was as high as 6 ppb or 0.006 ppm. (Add two hours to the displayed time in order to obtain the correct time.) 

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

The community air monitors’ readings are accessible at the Louisiana Dept. Of Environmental Quality’s   website right hand column On Air menu , select ‘site data’, select Meraux or Chal_Vista.   Also available at this link

Hydrogen sulfide is a poisonous gas.  It has been found in some drywall materials. Residents with contaminated drywall have reported nose bleeds and other health effects from the offgasing of H2S inside their homes.