Harmful Effects of Vaping Chart Health Edco I heard voices screaming in my head. It was terrifying., Figures from the Health Research Board show that since the beginning of last year, 169 young people sought treatment for problems with HHC can cause harm and is known to be addictive. For more information on the change in law and services available for anyone impacted visit gov.ie HHC HHC can cause harm and is known to be addictive. For more information on the change in law and services available for anyone impacted visit gov.ie HHC