The world is filled with trash but not all of it is visible to the human eye.

Microplastics, forever chemicals, and plastic litter on the beach are easy to spot, but they have not been noticed.

Both forms of pollution fall with the rain. While the potential threat of microplastics is a regular point of discussion, some researchers argue that the spread of other persistent synthetic compounds is less discussed.

Scientists in Europe are concerned that we have crossed a critical line. The presence of forever chemicals in our hydroosphere at values that exceed key guidelines means we have entered an unsafe operating space from which there is practically no return.

The world has violated the safe planetary limit for synthetic chemicals according to a cautionary paper.

Similar to microplastics, the potential health effects of long- lasting per- and polyfluoroalkyl substances are not known.

Government safety thresholds in the United States are largely unenforced due to lagging research and the fact that some types of PFAS are linked to cancer.

It will be too late if some chemicals turn out to be toxic in the future.

A global analysis of PFAS levels over the past ten years has found that often greatly exceed the US Environmental Protection Agency's advisory levels.

Researchers found that some chemicals exceed EPA guidelines in the Tibetan Plateau.

"Based on the latest US guidelines for PFOA in drinking water, there would be no safe drinking water anywhere in the world," says IanCousins.

Many people around the world expect rain to be safe to drink and it supplies many of our drinking water sources.

Nearly half of the drinking water in Sweden exceeded safety levels.

Water isn't the only thing that's impacted. This groundContamination regularly exceeds guideline values in Europe due to the presence of PFAS.

The Dutch government relaxed its guidelines after industry players in the country found it hard to meet safety standards.

As scientists learn more about what chemicals do to human health, the guidelines for the US are becoming more strict.

The US EPA lowered its safety threshold for some types of PFAS because they turned out to be more dangerous than thought.

The Environmental Working Group warned in 2020 that there were unsafe levels of PFAS in a lot of drinking water. This group has a history of overstating the health impacts of certain chemicals and, at the time, EWG's safety levels for PFAS in drinking water were lower than the EPA's guidelines.

It's no longer possible. The EPA health advisory for PFOA and PFOS was 70 parts per trillion. It's far, far lower with regards to PFOA and PFOS.

Half of the US population would be exposed to potentially harmful chemicals if the new levels were found.

There has been a decline in guideline values for PFAS in drinking water over the last two decades.

In the US, the drinking water guideline value for one well-known PFAS substance that is possibly carcinogenic has declined by over 30 million times.

That is a bad sign. It suggests that regulators have overlooked or underestimated the risks associated with some types of long- lasting manufactured chemicals, produced by the military and contained in products like Teflon, Scotchguard and foam.

Regardless of whether or not one agrees with our conclusion that the planetary boundary for PFAS is exceeded, it is still highly problematic that everywhere on Earth where humans reside recently proposed health advisories cannot be achieved without large investment in advanced clean up technology.

It will take decades before levels in land-based water and precipitation approach low picogram per liter levels, despite the fact that PFOS and PFOA were phased out by one of the major manufacturers.

The results of the recent analysis only consider four types of PFAS, which means that hundreds of other chemicals are being released into the environment at the same time.

Regulations are not keeping up with the problem.

The study was published in a scientific journal.