A team of chemists at Lake Superior State University, working with colleagues from Wayne State University, both in Michigan, and two representatives from JEOL U.S., a lab equipment maker, has found that some cannabis rolling papers contain high levels of heavy metals, which could be hazardous to smokers.
In their paper published in the journal ACS Omega, the group describes their analysis of many samples of several different types of cannabis rolling papers.
People who smoke marijuana use three main methods to burn the product: use a bong or a pipe or roll it in paper and smoke it as a joint. Prior research has shown that some marijuana has some amount of heavy metals in it, which could prove to be a health hazard for smokers, particularly for those who smoke often. Because of this, many states have enacted laws regulating such levels.
In this new study, the researchers noted that very little research has been done regarding burnable cones or the paper that is used to make joints to see if they are safe to use in this way. The team conducted tests in their lab to measure the amounts of heavy metals they contain.
The work by the group involved purchasing 53 commercially available samples of papers and cones and taking them back to their lab for testing. They noted that many of the papers they purchased had been colored to make them appear more pleasing than the standard white.
The researchers looked for the presence of 26 elements in the papers that could pose a health hazard, most of which were heavy metals. Standard chemistry tests measured the levels of such elements, which included burning samples to see if the heavy metals were present in the smoke that would enter the lungs of a user.
The researchers found mixed results. Heavy metal levels were very low in some samples, and very high in others, some of which they suggested, could present a health hazard for heavy users. High levels of copper were found in many of the colored papers, likely due to the pigments used.
The team concludes by noting that it would not be very difficult for makers of such products to remove heavy metals during the production process. They suggest state lawmakers take note of their findings and enact laws to force the makers of such products to reduce heavy metals to safe levels.
