The Arjenyattah epidemic. Home interview data and toxicological aspects.

In 1983, 949 cases of acute non-fatal illness consisting of headache, dizziness, blurred vision, abdominal pain, myalgia, and fainting occurred in the West Bank. Physical examination and biochemical tests were otherwise normal. There was no common exposure to food, drink, or agricultural chemicals among those affected. No toxins were consistently present in patients' blood or urine. Hydrogen sulphide gas was detected in low concentrations (40 parts per billion) at the site of the first outbreak. No other environmental toxins were found. The illness was thus of psychological origin and possibly triggered by the smell of hydrogen sulphide.