Knowns and unknowns on burden of disease due to chemicals: a systematic review .Annette Prüss-Ustün, Carolyn Vickers, Pascal Haefliger, Roberto Bertollini.Environmental Health 2011, 10:9doi:10.1186/1476-069X-10-9 /www.ehjournal.net/content/10/1/9 . 21 January 2011. abstract conclusions: The known burden due to chemicals is considerable. This information supports decisionmaking in programmes having a role to play in reducing human exposure to toxic chemicals. These figures present only a number of chemicals for which data are available, therefore, they are more likely an underestimate of the actual burden. Chemicals with known health effects, such as dioxins, cadmium, mercury or chronic exposure to pesticides could not be included in this article due to incomplete data and information. Effective public health interventions are known to manage chemicals and limit their public health impacts and should be implemented at national and international levels. See full text in PDF format.