Researchers examined samples of lung tissue from 17 people, all of whom had vapid and 70% consumed marijuana or cannabis oil. Two samples were taken from patients who died, according to the Mayo Clinic.
The accumulation of fatty substances, such as oil, was suspected of lung damage, but researchers said there was no evidence that they were the cause.
"Based on what we saw in our study, we suspect that most cases involve chemical contamination, toxic by-products or other harmful agents in liquids contained in lime liquids," Larsen said.
The question that remains for researchers is what these chemicals are that can cause injury. Larsen said it needed more investigation.
"While this epidemic is being investigated "The safest option is to refrain from using any electronic cigarette or anti-virus product," said state health worker Dr. Scott Harris in a statement Wednesday.
And just one day before that, both Virginia and New Jersey recorded a drowning death.
Fourteen other deaths have been identified nationwide as part of a multi-stage outbreak of lung injury: two in California, two in Kansas, two in Oregon, and one each in Illinois, Indiana, Minnesota, Missouri, Florida. , Mississippi and Nebraska.
CNN's Michael Nedelman contributed to this report.