Sources of human exposure: overview of water supplies as sources of boron.
Boron (B) is widely distributed in surface and groundwaters predominantly as undissociated boric acid, and is found in ocean waters at a mean level of approx 4.6 mg B/L. A recent analysis of US surface waters indicated that the 10th, 50th, and 90th percentile B levels were 0.010, 0.076, and 0.387 mg B/L, respectively. The same study found that the 50th and 90th percentile B levels in California drinking waters were 0.10 and 0.40 mg B/L, respectively. The overall mean B concentration in Canadian surface waters in 1988 was reported to be 0.16 mg B/L, with a few stations reporting concentrations above 2.0 mg B/L. Unusually high levels of B have been measured in human water supplies of northern Chile, with concentrations ranging from 0.31 to 15.2 mg B/L. River water sources of B in the UK and Northern Italy were found to range from 0.002 to 0.87 mg B/L, respectively, whereas German drinking waters had median and maximum B levels of 0.02 and 0.18 mg B/L, respectively. Bottled mineral water also represents a source of B exposure based on the largest reported survey of US and European products, with a mean level of 0.75 mg B/L and a range from <0.005 to 4.35 mg B/L. Thus, B intake from drinking water is highly variable and dependent on the geographic source, the quantities of water consumed and the water sources used to bottle other beverages.
Coughlin
J R
JR
Coughlin & Associates, Newport Coast, CA 92657, USA.
D001881:Borates; D001888:Boric Acids; D001895:Boron / Q000032:analysis* / Q000737:chemistry; D002170:Canada; D002677:Chile; D004781:Environmental Exposure; D005060:Europe; D006801:Humans; D008900:Mineral Waters / Q000032:analysis; D014481:United States; D014881:Water Supply
D001881:Borates; D001888:Boric Acids; D008900:Mineral Waters; C018851:borax; D001895:Boron; C032688:boric acid