Perchlorate in the Feed−Dairy Continuum of the Southwestern United States

• Published in: Journal of agricultural and food chemistry 2008-07, Vol.56 (13), p.5443-5450
• Main Authors: Sanchez, C. A, Blount, B. C, Valentin-Blasini, L, Lesch, S. M, Krieger, R. I
• Format: Article
• Language: English
• Subjects: Animal Feed - analysis; Animals; Biological and medical sciences; Cattle; dairies; dairy feed; drinking water; Feed and pet food industries; feed contamination; feed-dairy continuum; Female; food chain; food contamination; Food industries; forage crops; forage evaluation; Fundamental and applied biological sciences. Psychology; Iodine - analysis; Medicago sativa - chemistry; milk; Milk - chemistry; milk analysis; Milk and cheese industries. Ice creams; milk composition; milk quality; Nitrates - analysis; Perchlorate; perchlorates; Perchlorates - analysis; Southwestern United States; Thiocyanates - analysis; Toxicology in Agriculture and Food; Water - chemistry; Water Pollutants, Chemical - chemistry
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf0733923

Perchlorate has the potential to cause thyroid dysfunction by inhibiting iodide uptake by the sodium iodide symporter. Perchlorate-contaminated waters may lead to human exposure through drinking water and food chain transfer in crops by way of irrigation water. Perchlorate has been found in dairy milk collected nationally and internationally. This study was conducted to evaluate perchlorate in the feed-dairy continuum in the southwestern United States. All feed products collected at dairies in this study had detectable levels of perchlorate as analyzed by ion chromatography−tandem mass spectrometry. The calculated total perchlorate intake across dairies ranged from 1.9 to 12.7 mg/cow per day. The variation in total perchlorate intake across dairies was largely associated with variation in forage and silage products. Alfalfa products were the single most important source of perchlorate intake variability among dairies. The estimated perchlorate intake from drinking water ranged from 0.01 mg per cow per day and was generally less than 2% of the total perchlorate intake. The perchlorate content of milk ranged from 0.9 to 10.3 µg/L and was similar to levels reported by the Food and Drug Administration’s Total Diet Study. The perchlorate content of milk was significantly related to the presence of perchlorate in feed but the variation of perchlorate in milk could not be explained by feed intake alone.