Environmental exposures have been postulated to affect the pathogenesis of many human diseases including blood cancers and predisposition conditions such as clonal hematopoiesis (CH). There are few systematic studies that have determined the magnitude of CH in well-defined cohorts of environmental exposures. A team of NY researchers conducted deep sequencing analysis of 988 World Trade Center (WTC) responders (firefighters and emergency medical service) exposed to high levels of aerosolized dust, gases, and potential carcinogens associated with the World Trade Center (WTC) disaster to determine the prevalence of CH and the association between CH and leukemia. At ASH 2024 in San Diego we met Divij Verma (Blood Cancer Institute, Department of Oncology, Albert Einstein College of Medicine, New York), that reports on the findings.