The North American Mosaic has four overarching features. First, it is, to the extent feasible, based on comparable information on the status and trends of major indicators of the state of the environment in Canada,Mexico, and the United States. Second, the report confirms that these three countries together make up an incredibly complex, dynamic, and interconnected ecosystem in which humans play a dominant and decisive role. Third, the report raises important and sometimes disquieting questions concerning the sustainability of some current trends. Finally, the report is a reminder that our economic, social, and physical well-being are utterly dependent on the life-sustaining services provided by nature. This report emphasizes the importance of developing mutually compatible economic, social, and environmental goals and policies across the three-country region.

The understanding that some pesticides are more hazardous than others is well established. Recognition of this is reflected by the World Health Organization (WHO) Recommended Classification of Pesticides by Hazard, which was first published in 1975. The document classifies pesticides in one of five hazard classes according to their acute toxicity. In 2002, the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) was introduced, which in addition to acute toxicity also provides classification of chemicals according to their chronic health hazards and environmental hazards.