Soap’s dirty secret
Update: September 2, 2016 -- The U.S. Food and Drug Administration today issued a final rule establishing that over-the-counter consumer antiseptic wash products containing certain active ingredients, including triclosan and triclocarban, can no longer be marketed. The FDA originally proposed the rule after some data, including research from Rolf Halden’s team, suggested that long-term exposure to certain ingredients used in antibacterial projects could pose health risks. Manufacturers were unable to demonstrate that the ingredients are both safe for long-term daily use and more effective than plain soap and water in preventing illness.
That’s how long 95 percent of people spend washing their hands.
However, to kill germs effectively, you need to spend at least 20 seconds scrubbing, about the time it takes to sing “Happy Birthday” twice through, according to the Centers for Disease Control and Prevention.
Many people buy soaps containing antimicrobial chemicals like triclosan (TCS) and triclocarban (TCC) in the hopes of cleaning more efficiently. However, studies show that these products are no more effective than plain soap and water. And the 20-second rule still applies.
In our zest for cleanliness, we not only fail to kill germs correctly, but also may have unwittingly contributed to an environmental and human health mess.
“Most people don’t use personal care products correctly and are unaware of the legacy that they are leaving behind, which lasts decades or longer,” says Rolf Halden, director of the Center for Environmental Security at Arizona State University. “The widespread use of antimicrobial compounds offers no measurable benefit for the average consumer yet creates a legacy pollution that can be traced back for half a century in the sediments of our drinking water resources.”
Every day, those scant seconds send the active ingredients from thousands of products—antimicrobial soaps, cosmetics, disinfectants and sanitizers—cascading out of our homes into sewers. From there, a significant fraction breaks through wastewater treatment units to eventually settle into lakes and rivers, where it can persist for decades.
Halden, a professor in ASU’s School of Sustainable Engineering and the Built Environment, studies the broad interconnectedness of the water cycle and human health, with special emphasis on the role of man-made products and human lifestyle choices on environmental quality. It has increasingly led him on a journey from scientific discovery to reforming public policy.
Follow the water
“It’s very powerful to look into water, and to understand what is left over after treatment, and to trace the fate of what happens,” says Halden, whose “follow the water” mantra has served as a guidepost to his scientific career.
Halden’s team was the first to find significant concentrations of TCC and TCS dating back to the 1950s in sediments of New York’s Jamaica Bay and Baltimore’s Chesapeake Bay, where they were discharged in treated domestic wastewater. More recently, Halden found the same antimicrobial ingredients contaminating Minnesota’s freshwater lakes, released into nearby waters from various human activities.
“We first discovered TCC pollution in Baltimore, and over the years added hundreds of cities and streams to reveal nationwide contamination,” he says. “It turns out, if a chemical is not removed from water or destroyed during the wastewater treatment process, it leaves the plant in either reclaimed water or in sewage sludge.”
Sludge is often applied to agricultural land, where it recycles not only desirable nutrients, such as nitrogen and phosphorus, but also undesirable, harmful chemicals that may end up in crops and the food supply.
Halden’s team found a strong correlation between the level of contamination of wastewater treatment plant discharge and the population density of the surrounding region. The problem with these substances is that their chemical structure is mostly foreign to nature. This leaves natural breakdown mechanisms and enzymes ineffective in destroying them.
“In the built environment, it is us, the creators and inhabitants, who store the non-green, recalcitrant chemistry in our bodies, mostly in adipose tissue, and in women also in breast milk,” says Halden.
Antimicrobials have been detected in human blood and urine. The compound TCS was even found in 97 percent breast milk samples, placing an unnecessary risk on newborns’ health.
TCS and TCC are known endocrine disruptors. These mimic hormones found in people and wildlife, with potential adverse impacts on sexual and neurological development. In collaboration with Laura Geer from the State University of New York, Halden and his team found various antimicrobials in newborns in Brooklyn and observed decreased gestational age at delivery in mothers exposed to TCC.
Geer says the study also yielded a link between women with higher levels of butyl paraben, an antimicrobial commonly used in cosmetics, and shorter newborn lengths. The long-term consequences of this are not clear, but Geer adds that if this finding is confirmed in larger studies, it could mean that widespread exposure to these compounds will cause a subtle but large-scale shift in birth sizes.
The Minnesota legislature was so alarmed by these and other researchers’ findings that it instituted the first ban of problematic antimicrobials from all state agencies. Some companies, such as Johnson & Johnson and Procter & Gamble, have announced that they are phasing out the compounds from some products. At the federal level, the Food and Drug Administration and the Environmental Protection Agency are reviewing the use and effects of TCC and TCS, drawing in part on information relayed by Halden in publications and a congressional briefing.
The sewage never lies
TCS and TCC are at the top of modern society’s trash heap, ranking among the top ten pharmaceuticals and personal care products most frequently contaminating the environment and U.S. drinking water resources.
They are emblematic of something much larger—our 20th-century chemical legacy. Thousands of chemical byproducts, together with the pharmaceuticals we use, end up in our sewage and, ultimately, in surface waters.
A decade ago, the U.S. Geological Survey published a landmark study showing that 80 percent of 139 streams sampled from across the U.S. contained measurable levels of various organic wastewater contaminants.
With an array of new tools and support from the Virginia G. Piper Charitable Trust, Halden has built the first nationwide monitoring network, called the Human Health Observatory. It measures, using mass spectrometry, some 230 chemical and biological markers contained in wastewater that can serve to gauge the health of a city. The project began as a national effort and is now expanding internationally.
The beauty of this wastewater-based analysis strategy is that it can be performed on differing scales, from buildings to city blocks to neighborhoods or to the nation as a whole.
“Today, we have information on the chemistry used by and contained in 10 percent of the U.S. population—some 32 million people residing in over 160 cities across the nation,” says Halden. The tools are sensitive enough to measure everything from a spike in illicit drug consumption from a weekend rock festival to the use of birth control pills to emerging public health threats.
“So now our clients, or our patients, are the cities rather than individuals,” he adds. “The sewage never lies. It’s giving real information on what’s happening and provides an entry point for health interventions that can save lives by the thousands.”
Halden envisions the sewage pipeline becoming an information superhighway of all the public health data of a city—a treasure trove of information, all coming from human waste.
“That’s what we are working on right now. We want to develop a dashboard of public health for the United States and ultimately the world, and compare how different regulatory environments lead to different chemistries and different exposure and health profiles,” he says.
Trickling into regulation
Halden knows that monitoring alone will not quell the rising tide of emerging contaminants. Regulation holds the key to truly effecting change. In February 2011, Halden participated in a congressional briefing panel in Washington, D.C., about the public health dangers of TCC and TCS.
Unfortunately, Halden has studied and seen firsthand how slowly the regulatory gears turn at the federal level.
“We just completed an analysis of 143,000 peer-reviewed research papers to track the progress of what we call chemicals of emerging concern,” he says. “We found that it takes around 14 years from the point at which safety issues are raised about a chemical before scientists’ concern peaks and regulators act.”
The pathway from a chemical’s introduction into society to a regulatory ban can take decades. For instance, TCC and TCS were first patented in 1957 and 1964, respectively. Antimicrobials made their first appearance in commercial hand soaps in the 1980s. By 2001, 76 percent of liquid hand soaps contained these chemicals. Levels of TCC and TCS in people have increased by an average of 50 percent since 2004, according to the Centers for Disease Control and Prevention.
“And so, we are now bathing in the chemistry that was made in the 1950s, 60s and 70s,” says Halden. “I started to sit on the FDA committee in 2005; now we write the year 2016. The FDA entered into a consent decree that something needs to happen soon, but years of unnecessary exposure and pollution have taken place, leading to degradation of resources and threatening public health. That’s not a good path.”
Halden believes the regulatory agencies should also encourage industry to make products from benign or “green” chemicals. These are composed of basic, ubiquitous building blocks and chemical bonds, not ones that are rare in nature and cannot biodegrade. Safer options are feasible and available.
Synthetic chemicals are vital to our society. Halden believes we can make and use them responsibly to create a safer and better chemistry and public health of tomorrow. Ultimately, the power of consumers may trump the current chemical logjam at the federal regulatory agencies.
“The culture of fear leads people to make impulsive decisions and buy a lot of antimicrobial products that are not really needed. It's a profitable market to be in, but not one that is ultimately sustainable or a good idea,” Halden says. “What’s much faster is if people vote with their pocketbooks. Consumers need to be better informed so they don’t buy stuff that is not good for their bodies or the environment.”
The Center for Environmental Security (CES) is one of 15 centers in ASU’s Biodesign Institute and is jointly supported by ASU’s Global Security Initiative.