This report is mainly based on facts obtained from the following websites.
For a more detailed list of sources, please refer to the references section at the end of the report.
World Health Organization (http://www.who.int)
Center for Disease Control and Prevention (USA) (http://www.cdc.gov)
National Cancer Institute (USA) (http://www.cancer.gov)
Food and Drug Authority (http://www.fda.gov)
National Institute for Environmental Health and Safety (USA) (http://www.niehs.nih.gov)
Agency for Toxic Substances and Disease Registry (USA) (http://www.atsdr.cdc.gov)