Question:

What are the health implications of swimming in a pool with copper in the water?

Answer:

The Department of Water Affairs and Forestry sets down guidelines for water quality for human use in South Africa.

Their document, South African Water Quality Guidelines (second edition). Volume 1: Domestic Use, published in 1996 states on page 58 "it is recommended that the concentration of copper in potable water should not exceed 30 mg/l . . ."

"Potable" water refers to water that you can bath in, cook with and drink. You can obviously, therefore, also swim in it.

In order to achieve this concentration, one would have to simultaneously empty more than 15 bottles of Activator D into a normal-sized (i.e. 50 000 litre) swimming pool (see the calculations). Assuming the water was drinkable prior to this unlikely action, the water would still be drinkable afterwards, even with this amount of copper added.

The document also states:

• "High concentrations of copper impart a disagreeable taste to water, and consumption of such water is therefore highly unlikely." (page 57); and
    

• "Mitigatory measures to counteract the effects of having ingested excessive amounts of copper are usually unnecessary since, even at the threshold concentration for health effects, nausea and consequent vomiting result, which rid the body of copper." (page 58)

In other words copper cannot poison you because:

• You wont drink water with dangerous doses of copper as it tastes terrible; and
    

• Your body cannot accept high concentrations (greater than 30 mg/l) and will vomit it up if forced to drink it.

As a matter of interest, the concentration limit for "severe poisoning" is 200 mg/l, some 100 bottles of Activator D in a normal-sized pool.

Finally, copper sulphate is water soluble. It cannot, therefore, enter the human body through the skin which is impervious to water.

Detail Calculation

Activator D is a combination of a number of chemical compounds of which copper sulphate pentahydrate is one. Since we are looking at the concentrations of copper, assume that the factory totally misfires and, neglecting to mix in any other chemicals, fills a bottle to the brim with copper sulphate pentahydrate.

This is then a worst case scenario – a totally full bottle of copper sulphate pentahydrate.

Mass of CuSO₄.5H₂0 in full bottle : 500 g

Atomic Mass of Elements: 

Recommended Maximum Concentration of Cu in Potable (i.e. drinking) water

Bottles of CuSO₄.5H₂0 to add to pool to attain Recommended Maximum Concentration

Utilising the actual content of CuSO₄.5H₂0 in a bottle of Activator D (remembering that we have looked at an extreme example) the number of bottles required to attain the Recommended Maximum Concentration rises from 11.6 to more than 15 bottles.

* Department of Water Affairs and Forestry, 1996. South African Water Quality Guidelines (second edition). Volume 1: Domestic Use. Page 58.