"Lack of regulation has allowed these products to be marketed and sold without limits, including to pregnant women and youth." The American Society of Clinical Oncology called the regulations a "crucial step" in regulating tobacco products and understanding the risks and benefits of e-cigarettes
Everyone can have some personal reasons behind this but below are some of the common ones: To avoid expensive repairs from mechanics For convenience (one can use the socket to charge the gadgets anywhere) To use DIY ways to change minor faults such as blown fuse, sockets, etc
As for the enzymatic process, nicotine is converted into cotinine, which is the main metabolite, ensuring that around 7080% of nicotines filtration is done through the liver
A frequently cited study by the San Diego State University concluded that only one cigarette filter per liter of water is enough to kill half of the fishes in the water
References Papers of particular interest, published recently, have been highlighted as: Of importance Of major importance Litter Free Planet