title: Heated indoor swimming pools, infants, and the pathogenesis of adolescent idiopathic scoliosis: a neurogenic hypothesis.
abstract: BACKGROUND
  In a case-control study a statistically significant association was recorded between the introduction of infants to heated indoor swimming pools and the development of adolescent idiopathic scoliosis (AIS). In this paper, a neurogenic hypothesis is formulated to explain how toxins produced by chlorine in such pools may act deleteriously on the infant's immature central nervous system, comprising brain and spinal cord, to produce the deformity of AIS.
  
  
  OBJECTIVE
  Through vulnerability of the developing central nervous system to circulating toxins, and because of delayed epigenetic effects, the trunk deformity of AIS does not become evident until adolescence. In mature healthy swimmers using such pools, the circulating neurotoxins detected are chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Cyanogen chloride and dichloroacetonitrile have also been detected.
  
  
  METHODS
  In infants, the putative portals of entry to the blood could be dermal, oral, or respiratory; and entry of such circulating small molecules to the brain are via the blood-brain barrier, blood-cerebrospinal fluid barrier, and circumventricular organs. Barrier mechanisms of the developing brain differ from those of adult brain and have been linked to brain development. During the first 6 months of life cerebrospinal fluid contains higher concentrations of specific proteins relative to plasma, attributed to mechanisms continued from fetal brain development rather than immaturity.
  
  
  CONCLUSIONS
  The hypothesis can be tested. If confirmed, there is potential to prevent some children from developing AIS.
authors.affiliation: Scottish National Paediatric Spine Deformity Centre, Royal Hospital for Sick Children, Edinburgh, UK. m.mcmaster1@btinternet.com
authors.forename: Marianne E
authors.initials: ME
authors.lastname: McMaster
mesh_terms: D000097:Acetonitriles / Q000493:pharmacokinetics / Q000633:toxicity; D000293:Adolescent; D001812:Blood-Brain Barrier / Q000502:physiology; D002490:Central Nervous System / Q000254:growth & development / Q000503:physiopathology; D002648:Child; D002713:Chlorine / Q000493:pharmacokinetics / Q000633:toxicity*; D003486:Cyanides / Q000493:pharmacokinetics / Q000633:toxicity; D005260:Female; D006361:Heating; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008962:Models, Theoretical; D009055:Mouth / Q000502:physiology; D009498:Neurotoxins / Q000493:pharmacokinetics / Q000633:toxicity; D012143:Respiratory Physiological Phenomena; D012307:Risk Factors; D012600:Scoliosis / Q000139:chemically induced / Q000209:etiology* / Q000503:physiopathology; D012879:Skin Physiological Phenomena; D013131:Spine / Q000254:growth & development / Q000473:pathology*; D013551:Swimming Pools; D022882:Trihalomethanes / Q000493:pharmacokinetics / Q000633:toxicity
chemical_list: D000097:Acetonitriles; D003486:Cyanides; D009498:Neurotoxins; D022882:Trihalomethanes; D002713:Chlorine; C014430:cyanogen chloride; C051716:dichloroacetonitrile