ANDERSLOV, Sweden -- Several blond residents of a southern Swedish town were left with green hair after an unusual reaction between the water supply and the shower system of a number of new homes.
Authorities began investigating when a number of inhabitants of Anderslov complained that their hair suddenly turned green, Swedish newspaper Skanskan reported.
They tested the water supply in several homes to see if there was a high level of copper -- known to turn hair green -- but recorded only normal levels of the metal.
However, when hot water was left in the houses' water systems overnight, the amount of copper in it was found to increase to five or 10 times the normal amount.
Investigators concluded that the hot water must have peeled copper from the pipes and water heaters. The copper then was absorbed into the water, causing the shock hair color change when residents showered.
The problem was found to be worst in new homes, where pipes lacked coatings.
"The samples we took from older houses have lower copper levels," environmental engineer Johan Pettersson told Skanskan.
Residents were told wash their hair in cold water or live in an older house to avoid the problem.