As the plant dries or gets heated, THCA slowly changes into THC
the fibres (4) of the filter tow are arranged to have a particular curvature which is similar to the curvature of the filter shape where it meets the tobacco rod, and this allows the flow of the smoke stream to flow from the centre towards the outer edges of the filter (la), increasing the overall rate of filtration and the uniformity of filtration over the axial cross section compared with a filter in which the fibres have no such curvature
However, the laws started to change in 1988 after a settlement agreement between cigarette companies and particular state governments
1 2 Abby Hunter, Rachael Murray, Laura Asher et Jo Leonardi-Bee, The Effects of Tobacco Smoking, and Prenatal Tobacco Smoke Exposure, on Risk of Schizophrenia: A Systematic Review and Meta-Analysis , Nicotine & Tobacco Research: Official Journal of the Society for Research on Nicotine and Tobacco , vol