Filipino marine biologists discovered that beaches in the Philippines are heavily loaded with caffeine.

In a recent study, scientists from the University of the Philippines Marine Science Institute and the University at Buffalo in New York discovered high levels of caffeine and other drugs in beaches and watersheds of Boracay Island, Tubbataha Reef Nature Park, Davao Gulf in Davao City, Macalajar Bar in Cagayan de Ory City, and the Municipality of Mabini in Batangas.

In 2019, after examining samples of wastewater and natural water, the researchers found out that caffeine was the most abundant drug in all samples followed by acetaminophen, also known as paracetamol.

The samples were taken during the dry and rainy seasons from both densely and less populated areas, such as canals, wells, and drainage systems, as well as beaches, coasts, and diving sites. The caffeine levels were the highest during the dry season, when a lot of tourists visited the said areas.

In Boracay, the samples were collected twice, during its closure in 2018 and when it reopened to tourists.

Shyrill Mariano, the lead author of the study and UP MSI postgraduate student, said that they took samples in Boracay during its closure when there were few people on the island.

"We had a chance to take samples during Boracay's closed season…That was the point when there were few people so the concentration of contaminants detected were low, and when they opened in April 2019, the detections rose in the sites," Mariano said.

Although it naturally dilutes in water, caffeine has a different lifespan. Studies say that it has a half-life of 100 to 240 days in seawater which indicates that its amount would half within that time. Meanwhile, its half-life in riverine water is merely 1.5 days.

Paracetamol, on the other hand, has a half-life of 16 to 26 hours in rivers. Because of the "continuous input of untreated discharge," which allowed researchers to identify high amounts of caffeine despite the plant's short lifespan, the study highlighted the need for more water treatment plants in tourist destinations and locations near aquatic habitats.

According to previous studies, human bodies metabolize almost 100% of caffeine on which the direct disposal of coffee, soda, tea, and other caffeinated beverages may be the source of caffeine found in the water. Mariano added that it came from untreated wastewater from households.

"As of now, our wastewater process connections are not that developed, so if you dispose of beverages into kitchen sinks, instead of undergoing wastewater treatment, it could flow to canals connected to rivers or coastal areas," Mariano said.

This indicates that the absence of treatment facilities to remove the toxins from the water is the issue, not the closeness of cafés or other sources of caffeinated drinks to the coast.

Pharmaceutical concentrations were found to be very high in agricultural areas in Macajalar Bay and the Davao Gulf. The researchers inferred possible connections to the coffee-producing process because Davao is recognized as a local producer of the bean.

On the other hand, the study found that treated wastewater, primarily from hospitals with wastewater treatment systems, did not contain any appreciable amounts of caffeine or paracetamol. According to the study, untreated water has 50–100 times greater amounts of caffeine and paracetamol than treated water.

"Our study highlights the urgent need to establish wastewater treatment systems not only in Metro Manila but other key areas in the Philippines like tourist sites or regions that are becoming highly urbanized," Mariano said.