title: Age-dependent association of exposure to television screen with children's urinary melatonin excretion?
abstract: OBJECTIVE
  Changes in magnetic field are associated with a decrease in nocturnal urinary melatonin excretion. Television screens emit low and very low frequency electromagnetic waves (radiofrequencies and light) and exposure to them may be associated with a decrease in 24-hour melatonin in children's urine. Design and setting. An observational study in schools of Cavriglia, Italy, determined melatonin in 24-hour urines from 42 boys and 32 girls 6 to 13 years of age after one week of watching TV and after another week of abstaining from watching TV.
  In a gender- and age-dependent fashion, exposure to a television screen was associated with lower urinary melatonin concentrations, affecting particularly younger children at a pubertal stage when important changes in melatonin's time structure occur.
  
  
  CONCLUSIONS
  Additional work should test further relations to growth, maturation and development, focusing on any adverse effect from exposure to a television screen also on obesity from a neuro-hormonal viewpoint, quite apart from any decreased activity and/or other lifestyle alterations associated with watching TV.
authors.affiliation: Department of Pediatrics, University of Florence, Florence, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Salti
authors.forename: Roberto
authors.initials: R
authors.lastname: Tarquini
authors.forename: Stefano
authors.initials: S
authors.lastname: Stagi
authors.forename: Federico
authors.initials: F
authors.lastname: Perfetto
authors.forename: Germaine
authors.initials: G
authors.lastname: Cornélissen
authors.forename: Giacomo
authors.initials: G
authors.lastname: Laffi
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Mazzoccoli
authors.forename: Franz
authors.initials: F
authors.lastname: Halberg
mesh_terms: D000293:Adolescent; D000375:Aging / Q000378:metabolism; D002648:Child; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000652:urine*; D012727:Sex Characteristics; D013690:Television
chemical_list: D008550:Melatonin