Agent Found in Water Kills Plant Pollen

A mysterious compound found in tap water and some bottled water blocks the germination of plant pollen, and UC Irvine researchers want to know if the unknown agent could have a harmful effect on other organisms.

Prof. Franz Hoffmann said Thursday that the effect was produced by treated and untreated tap water from several Orange County wells and repeated with water samples from West Germany.

“The fact that a fundamental botanical process like pollen germination is inhibited by a factor in drinking water (that is) not included in water quality control (tests) causes some general health concern,” said Hoffman, an associate professor of developmental and cell biology whose findings were published last month in the scientific journal Environmental Pollution.

Hoffmann cautioned that there is “no indication to believe there is toxicity to humans” from the as-yet unidentified compound. But “there is no indication there isn’t.”

Concerned Southern California water officials downplayed the findings as premature and of doubtful application to humans.

“I would say there is a lot more research that has to be done before you can start making comments about toxic agents and health concerns,” said Marshall Davis, water quality laboratory manager for the Metropolitan Water District, which supplies much of Southern California’s drinking water.

“To imply that what affects pollen germination affects man, that seems to be quite a stretch of the imagination,” said Ronald Young, general manager of the Irvine Ranch Water District, where some of the water samples were taken.

Hoffman said he and co-researchers stumbled upon the findings while doing genetic engineering studies on tobacco plants.

They discovered that pollen subjected to tap water--instead of the usual distilled water--failed to germinate. The pollen grains deteriorated, and the culture medium became discolored even when tap water was diluted with 75% purified water.

The samples used on the pollen came from wells in Irvine and Yorba Linda that were 20 miles apart, Hoffmann said. Since the phenomenon was first observed 2 1/2 years ago, the same effects have been duplicated with treated and untreated water from across the county and even a sample from Stuttgart, West Germany.