Brain tumours (BTs) are one of the most frequent tumour types in young
people. We explored the association between tap water, exposure to
trihalomethanes (THM) and nitrate and neuroepithelial BT risk in young
people. Analysis of tap water consumption were based on 321 cases and
919 appendicitis controls (10-24 years old) from 6 of the 14
participating countries in the international MOBI-Kids case-control
study (2010-2016). Available historical residential tap water
concentrations of THMs and nitrate, available from 3 countries for 86
cases and 352 controls and 85 cases and 343 for nitrate, respectively,
were modelled and combined with the study subjects’ personal consumption
patterns to estimate ingestion and residential exposure levels in the
study population (both pre-and postnatal). The mean age of participants
was 16.6 years old and 56% were male. The highest levels and widest
ranges for THMs were found in Spain (residential and ingested) and Italy
and in Korea for nitrate. There was no association between BT and the
amount of tap water consumed and the showering/bathing frequency. Odds
Ratios (ORs) for BT in relation to both preand postnatal residential and
ingestion levels of THMs were systematically below 1 (OR = 0.37
(0.08-1.73)) for postnatal average residential THMs higher than 66 mu
g/L. For nitrate, all ORs were above 1 (OR = 1.80 (0.91-3.55)) for
postnatal average residential nitrate levels higher than 8.5 mg/L, with
a suggestion of a trend of increased risk of neuroepithelial BTs with
increasing residential nitrate levels in tap water, which appeared
stronger in early in life. This, to our knowledge, is the first study on
this topic in young people. Further research is required to clarify the
observed associations