Neurological disease or intellectual disability among sons of female Swedish dental personnel.
OBJECTIVE
Prenatal exposure to elemental mercury may be a potential hazard for the offspring of female dental personnel working with dental amalgam. The aim of this study was to investigate whether potential in utero exposure to mercury might have affected the development of nervous system of the sons of Swedish female dental personnel leading to an increased risk of neurological disease or intellectual disability.


METHODS
We used national Swedish registers to investigate risks for diseases potentially related to adverse effects on neurodevelopment. Sons of female dentists (n=1690) and dental nurses (n=10,420) were compared with cohorts consisting of sons of other female healthcare personnel. Due to changes in mercury exposure in dentistry during the study period, analyses were stratified by decade of birth. Hazard ratios (HRs) were calculated using Cox proportional hazard models.


RESULTS
We found no elevated risk for neurological disease, epilepsy or intellectual disability among the sons of dental personnel during any of the decades studied. HRs for neurological disease among the dental nurse cohort were even below 1.00 during the 1970s and 1980s. A low number of events resulted in uncertainty regarding results in the dentist cohort.


CONCLUSIONS
We did not find any support for the hypothesis that mercury exposure in Swedish dentistry during the 1960s, 1970s or 1980s had any effect on the incidence of neurological disease or intellectual disability among the sons of female dental personnel. Our results imply that current use of dental amalgam should not represent an elevated risk for neurological disease or intellectual disability among the offspring of dental personnel.
Niko
N
Vähäsarja
Scott
S
Montgomery
Gunilla
G
Sandborgh-Englund
Anders
A
Ekbom
Jan
J
Ekstrand
Peggy
P
Näsman
Aron
A
Naimi-Akbar
D015331:Cohort Studies; D003723:Dental Amalgam / Q000009:adverse effects / Q000266:history; D003797:Dental Staff; D003816:Dentists, Women; D004827:Epilepsy / Q000209:etiology; D005260:Female; D049673:History, 20th Century; D006801:Humans; D008607:Intellectual Disability / Q000209:etiology*; D008297:Male; D008628:Mercury / Q000009:adverse effects / Q000266:history; D009422:Nervous System Diseases / Q000209:etiology*; D009679:Nuclear Family; D009726:Nurses; D016273:Occupational Exposure / Q000009:adverse effects* / Q000266:history; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000209:etiology* / Q000266:history; D012042:Registries; D012307:Risk Factors; D013548:Sweden
D003723:Dental Amalgam; D008628:Mercury