Activists of Environment Greenpeace perform next to a giant life ring, during talks on climate change, in Cancun beach December 10, 2010. REUTERS/Henry Romero (MEXICO - Tags: POLITICS ENVIRONMENT)
Activists of Environment Greenpeace perform next to a giant life ring, during talks on climate change, in Cancun beach December 10, 2010. Credit: Reuters/Henry Romero

(Reuters) - Pollutants ranging from pesticides to illicit drugs have been found in fresh water aquifers beneath a Caribbean resort in Mexico and could damage future tourism unless the region cleans up, a U.N.-backed study said on Sunday.

It said that samples taken from a labyrinth of water-filled caves beneath the "Riviera Maya" south of the city of Cancun showed contamination mainly from sewage, as well as from highways or even golf courses.

The amounts of pollution, including tiny traces of cocaine excreted in sewage, were not considered a health threat today but tighter controls were needed since the region's population was projected to surge tenfold by 2030, it said.

"The region has to pay more attention to sustainable development practices and minimise pollution," said lead author Chris Metcalfe, of Canada's Trent University and the U.N. University's Institute for Water, Environment and Health.

"If they let things go, they will kill the goose that lays the golden egg -- tourism," he told Reuters of an area with attractions including palm-fringed beaches, scuba-diving and Mayan ruins at Tulum.

The study, in the journal Environmental Pollution, did not estimate the cost of limiting pollution in the area.

Traces of shampoo, toothpaste, perfumes, caffeine and nicotine were also found in the water, as well as pesticides -- apparently from golf courses in a region which has little agriculture -- and pollution from cars and trucks.


The polluted water seeps into the system of caves beneath the Riviera Maya that flows into the Caribbean Sea.

The pollution may have contributed, along with over-fishing disease and climate change to a loss of about 50 percent of reefs off the coast since 1990, the study said.

The region was suffering problems similar to those of parts of Florida decades ago that had been successfully contained. Mexico had about 22 million foreign tourists in 2009, making it the 10th most visited country, according to U.N. data.

"It is essential to develop and maintain adequate wastewater treatment infrastructure," the study said. Only 32 percent of the population in the state of Quintana Roo have municipal wastewater treatment systems.

It urged a halt to a practice of pumping sewage into a layer of salty water under the aquifers. And it recommended laying impermeable liners beneath golf courses, as done in Florida, to prevent the run-off of pesticides. Other recommendations were to preserve remaining mangroves to protect the coasts.