In May 2011, students at LeRoy Central School District in northwestern New York State started exhibiting tics, spasms and nonsense speech. Some even claimed to suffer blackouts and seizures. A total of 19 students from various grades and classes have reported symptoms. After searching for potential infectious causes, the school district last week approved further environmental tests, according to Nature.
New York State Health Department investigators have ruled out some environmental factors and infectious agents, including Streptococcus, which can cause a tic-like syndrome called PANDAS or PANS for Pediatric Acute-onset Neuropsychiatric Syndrome.
Although investigators found no contaminants in the air or water within the school, the building is located some 5 kilometers from the site of a 1970 chemical spill that released "cyanide crystals" and trichloroethene (TCE) into the surrounding area, and some worry that this could be affecting the students. Though TCE has been linked to conditions such as cancer, liver damage, nausea, as well as increased risk of Parkinson's, the development of tics is not listed among the observed symptoms of TCE exposure. TCE levels were not elevated in the school water.