While there has been some debate as to whether vape related illnesses and deaths this year were limited to tobacco related vaping or extended to cannabis related vaping as well, THC, the active ingredient in marijuana, was found in 23 of the 29 samples tested in a study officials said recently, while nicotine was detected in 16 samples, which came from 10 different states across the country, the officials said.

Dank Vapes was the most commonly used THC product among patients who developed a deadly vaping illness, though it’s “unlikely” that a single brand caused the national outbreak, the Centers for Disease Control and Prevention said in a report Friday.

The mysterious illness, called EVALI, has hospitalized 2,291 people across the country and killed 48 people since reports of it started emerging earlier this year. Health officials quickly linked the illness to vaping but were struggling to identify what exactly was making people sick.

Dank Vapes, which CDC classifies as counterfeit products “of unknown origin,” appeared to be the most heavily used product, with more than half of hospitalized patients claiming they vaped it. TKO, Smart Cart and Rove were other popular brands among patients. However, which products patients used varied depending on the location of the smokers.

According to the CDC, “Recent CDC laboratory testing of bronchoalveolar lavage (BAL) fluid samples (or samples of fluid collected from the lungs) from 29 patients with EVALI submitted to CDC from 10 states found vitamin E acetate in all of the BAL fluid samples.  Vitamin E acetate is used as an additive in the production of e-cigarette, or vaping, products. This is the first time that we have detected a potential chemical of concern in biologic samples from patients with these lung injuries.”

“The nationwide diversity of THC-containing products reported by EVALI patients highlights that it is not likely a single brand … is responsible for the EVALI outbreak, and that regional differences in THC-containing products might be related to product sources,” the CDC said.

Vitamin E oil, famous for its wide use in skincare and beauty products, is increasingly being used to dilute THC vaping liquids.

“Although it appears that vitamin E acetate is associated with EVALI, many substances and product sources are being investigated, and there might be more than one cause,” the agency said.

Investors who are concerned about the effects of vaping and tobacco in general could consider healthcare ETFs like the Fidelity MSCI Health Care ETF (FHLC) or the Vanguard Health Care ETF (VHT), while those who would like to invest in rising tobacco technology trends could consider the Consumer Staples Select Sector SPDR Fund (XLP) or the iShares Global Consumer Staples ETF (KXI).

For more market trends, visit ETF Trends.