NEW HAVEN >> Trillions of plastic microbeads are flowing out of wastewater treatment plants and into the nation’s waters daily, environmental activists said Friday.

While Connecticut has passed a state law that will prohibit the sale of products containing plastic microbeads by the end of the decade, Connecticut lawmakers and environmental activists say that’s not good enough.

“One state alone can’t solve this problem,” U.S. Sen. Chris Murphy, D-Conn., said Friday morning on the shores of Long Island Sound. “Ultimately, we need a national law.”

Murphy earlier this year sponsored the Microbead-Free Waters Act in Congress that, if passed, would ban the sale of microbeads nationally by January 2018. Microbeads are not biodegradable and often are found in toothpastes and facial cleansers.

On Friday, Murphy took the call to action one step further and sent a letter to manufacturers that use plastic microbeads asking them to voluntarily remove the tiny plastic particles from their products. The letter was also signed by U.S. Sens. Richard Blumenthal, D-Conn., and Kristen Gillibrand, D-N.Y.

“Unilever, a multinational corporation whose U.S. headquarters are based in Connecticut, has pledged to completely phase out microbeads from all of their products by 2015. Johnson & Johnson and L’Oreal have also begun voluntarily eliminating the use of microbeads in their products. We urge you to follow the lead of these institutions by wielding your influence to curb the availability of these harmful products in U.S. stores,” Murphy wrote in the letter.

This past summer, professor Vincent Breslin from Southern Connecticut State University performed the first studies on the microbead presence in Long Island Sound. Breslin said his research was inspired by the Connecticut legislation that phases out sale of microbeads by 2017. Breslin said that prior research on plastic microbeads in other parts of the country has shown that they can pass through wastewater treatment facilities.

Using a fine mesh net, Breslin and his team combed the waters of the Sound this summer and found microbeads. He estimates that 8 trillion microbeads make it into U.S. waters daily. “(The study) documents the need for us to take some action,” Breslin said.

The microbeads, while in the water, can absorb contaminants or pollutants, Breslin said, and then when fish filter feed, they absorb those chemicals and ultimately, humans can be harmed.

Cleaning plastics out of the nation’s waters will not stop with a microbead ban, but it’s a start, State Rep. James Albis, D-East Haven, said Friday at the press conference.

“We need to ensure we get this large subset of microbeads out of our waters,” he said.

Albis is one of the co-chairmen of the state legislature’s Environment Committee and he thanked Murphy for taking this issue to the Capitol.

The research being done on the impact of microbeads on the Sound is still new, but Louis Burch from Citizens Campaign for the Environment said that other research on microbead impacts around the country corroborates Breslin’s findings. He said that with billions of microbeads entering the Sound every year, the ban has to come from more than Connecticut.

“We know Long Island Sound is still vulnerable to this type of pollution,” Burch said, referencing the threat of wastewater from New York City. “These particles are found in literally thousands of products on the market today.”

Burch said that to avoid buying products with plastic microbeads, consumers should check labels for polypropylene and polyethylene.

“We believe the companies that make these products can do more,” Murphy said. “You can still get a good facial cleanser or good shampoo without microbeads.”