Boron

3. What levels of boron are found?

• 3.1 What levels of boron are there in the environment?
• 3.2 What levels of boron are humans exposed to?

3.1 What levels of boron are there in the environment?

The source document for this Digest states:

Boron occurs in soils at concentrations ranging from 10 to 300 mg/kg (average 30 mg/kg), depending on the type of soil, amount of organic matter, and amount of rainfall. Concentrations of boron in surface water are dependent on such factors as the geochemical nature of the drainage area, proximity to marine coastal regions, and inputs from industrial and municipal effluent discharges. Concentrations of boron in surface water range widely, from 0.001 to as much as 360 mg/litre. However, mean boron concentrations for waters of Europe, Pakistan, Russia, and Turkey are typically well below 0.6 mg/litre. Concentrations of boron in water in Japan, South Africa, and South America are generally below 0.3 mg/litre. Typical boron concentrations in North American waters are below 0.1 mg/litre, with about 90% at or below 0.4 mg/litre.

Boron accumulates in aquatic and terrestrial plants but does not magnify through the food-chain. Concentrations of boron have been shown to range between 26 and 382 mg/kg in submerged aquatic freshwater plants, from 11.3 to 57 mg/kg in freshwater emergent vegetation, and from 2.3 to 94.7 mg/kg dry weight in terrestrial plants. Based on wet weights, boron concentrations in marine invertebrates and fish are similar to the levels found in the exposure media, between 0.5 and 4 mg/kg. The bioconcentration factor for two freshwater fish species was found to be 0.3.

Boron concentrations in ambient air range from <0.5 to approximately 80 ng/m³, with an average over the continents of 20 ng/m³.

Source & ©: IPCS "Environmental Health Criteria (EHC) 204 ,"
Summary of the Report, Chapter 1.1.2
For more information, see the full IPCS document
Environmental Levels and Human Exposure , Chapter 5

For details on boron in:	See the full IPCS assessment:
Groundwater	Chapter 5.1 , section 5.1.2.1
Surface water	Chapter 5.1 , section 5.1.2.2

3.2 What levels of boron are humans exposed to?

The source document for this Digest states:

Close similarity of boron concentrations in groundwater, fresh surface water, and drinking-water indicates that boron is not removed in the treatment of groundwater and fresh surface water used for drinking-water.

Intakes of boron for humans are expected to be 0.44 µg/day from ambient air, 0.2-0.6 mg/day from drinking-water, and 1.2 mg/day from the diet. Average boron intake from the soil is considered to be 0.5 µg/day. A reasonable estimate of boron exposure from consumer products is 0.1 mg/day.

Source & ©: IPCS "Environmental Health Criteria (EHC) 204 ",
Summary of the Report, Chapter 1.1.2
For more information, see the full IPCS document
Environmental Levels and Human Exposure , Chapter 5

For details on exposure from:	See the full IPCS assessment:
Diet	Chapter 5, section 5.2.4
Drinking-water	Chapter 5, section 5.2.2
Consumer products	Chapter 5, section 5.2.5
Soil	Chapter 5, section 5.2.3
Air	Chapter 5, section 5.2.1
Occupational Exposure	Chapter 5, section 5.3