House dust concentrations of organophosphate flame retardants in relation to hormone levels and semen quality parameters.
BACKGROUND
Organophosphate (OP) compounds, such as tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and triphenyl phosphate (TPP), are commonly used as additive flame retardants and plasticizers in a wide range of materials. Although widespread human exposure to OP flame retardants is likely, there is a lack of human and animal data on potential health effects.


OBJECTIVE
We explored relationships of TDCPP and TPP concentrations in house dust with hormone levels and semen quality parameters.


METHODS
We analyzed house dust from 50 men recruited through a U.S. infertility clinic for TDCPP and TPP. Relationships with reproductive and thyroid hormone levels, as well as semen quality parameters, were assessed using crude and multivariable linear regression.


RESULTS
TDCPP and TPP were detected in 96% and 98% of samples, respectively, with widely varying concentrations up to 1.8 mg/g. In models adjusted for age and body mass index, an interquartile range (IQR) increase in TDCPP was associated with a 3% [95% confidence interval (CI), 5% to 1%) decline in free thyroxine and a 17% (95% CI, 432%) increase in prolactin. There was a suggestive inverse association between TDCPP and free androgen index that became less evident in adjusted models. In the adjusted models, an IQR increase in TPP was associated with a 10% (95% CI, 219%) increase in prolactin and a 19% (95% CI, 30% to 5%) decrease in sperm concentration.


CONCLUSIONS
OP flame retardants may be associated with altered hormone levels and decreased semen quality in men. More research on sources and levels of human exposure to OP flame retardants and associated health outcomes are needed.
Meeker
John D
JD
Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan 48109, USA. meekerj@umich.edu
Stapleton
Heather M
HM
D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000032:analysis* / Q000633:toxicity; D004391:Dust / Q000032:analysis*; D005411:Flame Retardants / Q000032:analysis* / Q000633:toxicity*; D006728:Hormones / Q000097:blood / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010755:Organophosphates / Q000032:analysis* / Q000633:toxicity; D009943:Organophosphorus Compounds / Q000032:analysis / Q000633:toxicity; D017905:Phosphites / Q000032:analysis / Q000633:toxicity; D012661:Semen / Q000166:cytology / Q000187:drug effects*; D013076:Sperm Count; D055815:Young Adult
D000393:Air Pollutants; D004391:Dust; D005411:Flame Retardants; D006728:Hormones; D010755:Organophosphates; D009943:Organophosphorus Compounds; D017905:Phosphites; C013318:triphenyl phosphite; C016805:tris(1,3-dichloro-2-propyl)phosphate