Thyroid function in Danish greenhouse workers.
BACKGROUND
From animal studies it is known that currently used pesticides can disturb thyroid function.


METHODS
In the present study we investigated the thyroid function in 122 Danish greenhouse workers, to evaluate if greenhouse workers classified as highly exposed to pesticides experiences altered thyroid levels compared to greenhouse workers with lower exposure. Serum samples from the greenhouse workers were sampled both in the spring and the fall to evaluate if differences in pesticide use between seasons resulted in altered thyroid hormone levels.


RESULTS
We found a moderate reduction of free thyroxine (FT4) (10-16%) among the persons working in greenhouses with a high spraying load both in samples collected in the spring and the fall, but none of the other measured thyroid hormones differed significantly between exposure groups in the cross-sectional comparisons. However, in longitudinal analysis of the individual thyroid hormone level between the spring and the fall, more pronounced differences where found with on average 32% higher thyroid stimulating hormone (TSH) level in the spring compared to the fall and at the same time a 5-9% lower total triiodthyroxin (TT3), free triiodthyroxine (FT3) and FT4. The difference between seasons was not consistently more pronounced in the group classified as high exposure compared to the low exposure groups.


CONCLUSIONS
The present study indicates that pesticide exposure among Danish greenhouse workers results in only minor disturbances of thyroid hormone levels.
Toft
Gunnar
G
Department of Occupational Medicine, Aarhus University Hospital, Norrebrogade 44, build 2C, DK-8000 Aarhus C, Denmark. gutof@as.aaa.dk
Flyvbjerg
Allan
A
Bonde
Jens Peter
JP
D000293:Adolescent; D000328:Adult; D000383:Agriculture; D003718:Denmark; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D010575:Pesticides / Q000633:toxicity*; D012621:Seasons; D013959:Thyroid Diseases / Q000139:chemically induced*; D013963:Thyroid Hormones / Q000097:blood
D010575:Pesticides; D013963:Thyroid Hormones