[Blood and urine lead levels in children with attention deficit hyperactivity disorder].

Background: Attention deficit hyperactivity disorder is the most common neuropsychiatric disorder in children; symptoms can persist into adult life by 60 %. Our objective was to quantify the levels of lead in blood and urine in pediatric patients with attention deficit hyperactivity disorder.

Methods: We did an observational study which included a captive population of children diagnosed with attention deficit hyperactivity disorder in the mental health service of Hospital General, from Centro Médico Nacional La Raza.

Father's occupational exposure to carcinogenic agents and childhood acute leukemia: a new method to assess exposure (a case-control study).

Background: Medical research has not been able to establish whether a father's occupational exposures are associated with the development of acute leukemia (AL) in their offspring. The studies conducted have weaknesses that have generated a misclassification of such exposure. Occupations and exposures to substances associated with childhood cancer are not very frequently encountered in the general population; thus, the reported risks are both inconsistent and inaccurate.