A chemical linked to widely used agricultural fungicides and commonly found as a residue on food may be associated with girls starting their periods earlier, according to new research from Spain. The team examined markers of exposure to several modern pesticides, including insecticides and fungicides that can act as endocrine-disrupting chemicals, substances that interfere with the body's hormones. Girls with detectable levels of TCPy, a metabolite linked to the insecticide chlorpyrifos, tended to reach menarche later than girls with undetectable levels. They also highlighted several limitations, including the fact that pesticide exposure was estimated from urine samples taken at a single point in childhood. Age at menarche and exposure to non-persistent pesticides in Spanish girls from the INMA (environment and childhood) project.