UPDATE: On January 23 2014, hydrogen sulfide levels in neighborhood measured 30 ppb. In the State of California, this level of hydrogen sulfide would violate the health standards.
St Bernard Parish residents have been exposed to more hydrogen sulfide than the daily exposure level recommended by the EPA. Hydrogen sulfide is a gas which causes deleterious effects at chronic low level exposures of 0.0014 ppm (1.4 ppb). H2S can cause genetic damage, plus serious and permanent central nervous system damage. .
Health effects from chronic low level exposure include the burning and tearing of eyes, cough, shortness of breath, and for asthmatics, difficulty breathing. The effects may be delayed for several hours, or sometimes several days, when exposed to low level concentrations. Chronic exposure causes eye inflammation, headache, fatigue, irritability, insomnia, digestive disturbances and weight loss. Researchers found the following demonstrable symptoms resulting from chronic exposure to H2S: changes in brain density, abnormal neurobehavioral function, headache, altered mood states such as depression, fatigue, and tension, memory loss, pronounced deficits in balance and reaction time, dizziness, insomnia, overpowering fatigue, and reduced sense of smell.