Incident thyroid disease in female spouses of private pesticide applicators

[helvella]

Thought this might be of some interest - especially to any with contacts in agriculture and pest control, but also more generally. After all, many of us have some exposure to such compounds.

I do find it surprising that any of the compounds is associated with decreased risk.

Environ Int. 2018 Jun 13;118:282-292. doi: 10.1016/j.envint.2018.05.041. [Epub ahead of print]

Incident thyroid disease in female spouses of private pesticide applicators.

Shrestha S1, Parks CG1, Goldner WS2, Kamel F1, Umbach DM3, Ward MH4, Lerro CC4, Koutros S4, Hofmann JN4, Beane Freeman LE4, Sandler DP5.

Author information

1 Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.

2 University of Nebraska Medical Center, Omaha, NE, USA.

3 Biostatistics and Computational Biology Branch, Research Triangle Park, NC, USA.

4 Occupational and Environmental Epidemiology Branch, National Cancer Institute, Rockville, MD, USA.

5 Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA. Electronic address: [e-mail].

Abstract

BACKGROUND:

Little is known about modifiable risk factors for thyroid disease. Several pesticides have been implicated in thyroid disruption, but clinical implications are not clear.

OBJECTIVE:

We assessed associations between pesticide use and other farm exposures and incident hypothyroidism and hyperthyroidism in female spouses of farmers in the Agricultural Health Study (AHS).

METHODS:

We used Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals for risk of thyroid disease in 24,092 spouses who completed at least one follow-up questionnaire.

RESULTS:

We identified 1627 hypothyroid and 531 hyperthyroid cases over 20 years of follow-up. The fungicides benomyl, maneb/mancozeb, and metalaxyl, the herbicide pendimethalin, and among those over 60 years of age the insecticides parathion and permethrin (applied to crops) were associated with elevated hypothyroidism risk, with HR ranging from 1.56-2.44. Conversely, the insecticide phorate, and the herbicides imazethapyr and metolachlor were associated with decreased risk (HR ranging 0.63-0.73), as were long-term farm residence and other farm-related activities (HR ranging 0.69-0.84). For hyperthyroidism, the insecticide diazinon, the fungicides maneb/mancozeb, and the herbicide metolachlor were associated with increased risk (HR ranging 1.35-2.01) and the herbicide trifluralin with decreased risk (HR: 0.57).

CONCLUSIONS:

Several individual pesticides were associated with increased risk of hypothyroidism and hyperthyroidism, although some pesticides were associated with decreased risk. Some of the findings, specifically associations with fungicides, are consistent with results from an earlier analysis of prevalent diseases in AHS spouses.

Published by Elsevier Ltd.

KEYWORDS:

Agricultural Health Study; Hyperthyroidism; Hypothyroidism; Pesticides

PMID: 29908479

DOI: 10.1016/j.envint.2018.05.041

ncbi.nlm.nih.gov/pubmed/299...

[shaws Administrator]

Thanks for posting and very informative. In hot countries just before the heat increases many homes and buildings are treated with insecticides at least once a year.

[helvella Administrator Thyroid UK]

Poisons act in numerous ways. That these particular substances appear to cause thyroid issues is, I feel, the relevant point.

[penny]

As you say, it is surprising that there is any decreased risk with chemical exposure.

I grew up on a farm which was almost organic, only because of lack of money. We had a dairy herd and I drank untreated milk. (A scientist neighbour thought that this would account for my lack of allergies.) However, the farm was located near a major refinery and petro-chemical complex and there were times when we had to keep the windows shut in the house due to the terrible smell. (I remember a couple of ‘suits’ calling at the farm after my mother had complained of a smell which had permeated the neighbourhood for days, and that one of them said that he was surprised that we could smell anything over the smell of manure! Worse than this was when there was a fallout of ash over the crops and the leaves shrivelled. Nothing was ever done about any of this as the company running the complex was/is very powerful and a big employer.

I have always wondered why I should be hypo. and have been hypo since my teens. I was always extremely fit, slim and with a brain that worked, until hypo. that is. I was quite premature, 4.5 lbs, but grew quickly and am now 5’10” tall and weigh...hmm, I’ll keep that to myself. Did the levels of toxic substances affect my thyroid?

Thanks for finding and publishing this.

[FancyPants54 in reply to penny]

I'm not saying that the ash wasn't toxic, because I don't know. But ash coating a plant will cause the leaves to wither and die, toxic or not. The leaves can't photosynthesise with a coating like that. If it wasn't washed off quickly they would die.

[Hidden]

Thank you for the article, interesting reading.

In most of the villages here in France they now use mechanical means to remove weeds. Round Up is banned. It is difficult to buy fresh organic food here most of the food is locally grown and sprayed within an inch of it's life.

I grow some of my own vegetables but most of what I buy here is sprayed. I shall be glad to return to the UK.

I read an article last month that mentioned women in a village in USA where apples orchards are, there was a huge increased in the amount of cancer also thyroid problems.

[FancyPants54]

I wonder why they followed the wives and not the farmers applying the pesticides, who must have immediate access to higher doses of the stuff.

I've sometimes wondered if the fall out from Chernobyl has had an effect on thyroid disruption in Europe. Remember Welsh lamb was affected for several years. It came this far. We've probably all ingested some of that.

[Hidden]

No it is not banned you are correct but most villages do not use it now. It is also under lock and key in most shops.