high hydrogen sulfide levels

Hydrogen sulfide levels in the neighborhood on Monday measured over 30 parts per billion H2S.  The EPA recommended level of 1.4 parts per billion (ppb) daily exposure to hydrogen sulfide (H2S) was exceeded throughout the month of September  at all three community air monitors.  .…..inhaling more than this concentration on a daily basis poses an appreciable risk of deleterious effects.

http://www.epa.gov/iris/toxreviews/0061tr.pdf . "Exposure to lower concentrations can result in eye irritation, a sore throat and cough, nausea, shortness of breath, and fluid in the lungs." "Long-term, low-level exposure may result in fatigue, loss of appetite, headaches, irritability, poor memory, and dizziness."

http://en.wikipedia.org/wiki/Hydrogen_sulfide
http://concernedcitizensaroundmurphy.blogspot.com/2012/02/hydrogen-sulfide-exposure.html

The State of California air quality standard limits hydrogen sulfide to 30 ppb H2S; the State of Louisiana has no such standard.