The SYNERGY project is a pooled analysis of case–control studies on the joint effects of occupational carcinogens in the development of lung cancer. The initial aim of SYNERGY was to study the joint effects of occupational lung carcinogens and smoking. As of December 2011, data from 14 case–control studies conducted by renowned research groups in Europe and North America had been pooled, and the database contains individual lifetime data on occupations and smoking for more than 16 900 lung cancer cases and more than 20 950 control subjects.

The unique aspect of the SYNERGY project is its innovative strategy for assessing occupational exposures. The project started by focusing on exposure to asbestos, polycyclic aromatic hydrocarbons (PAHs), nickel, chromium, and respirable crystalline silica. Quantitative exposure measurements were collected from large national or industry-specific exposure databases in Europe and Canada. SYN-JEM, a job-exposure matrix based on these measurements, was used to assign exposure to each study participant. More recently, JEMs have been developed for benzene and diesel engine exhaust.

The SYNERGY project was funded by the German Social Accident Insurance (DGUV) and is coordinated by the International Agency for Research on Cancer (IARC/WHO) and the Institute for Risk Assessment Sciences at Utrecht University (IRAS).