Forty years ago, chemical pollution was the stuff that spewed from tailpipes, smokestacks, and sewers. Rivers burned, fish died, and forests withered under acid rain until Congress passed strict laws to curb the flood of manmade chemicals pouring into our waterways and atmosphere.
Man-made and naturally occurring chemicals pervade modern life. Here are a few that have been linked to human health problems.
However, 40 years ago there was little consideration of the chemicals that we were pouring into our bodies. The chemicals we use to sanitize our hands, package our foods, and keep our beds from going up in flames have seeped into our bodies in ways that were unimaginable a generation ago. Today, we are marinating in antibacterials, hormone disruptors, and flame retardants.
Man-made and naturally occurring chemicals pervade modern life. Here are a few that have been linked to human health problems.
“There are more than 80,000 man-made chemicals in existence today, and an estimated 2,000 new chemicals are introduced each year,” said Craig Marcus, a toxicologist at Oregon State University. “We encounter thousands of them every day, in food, kitchenware, furniture, household cleaners, and personal care products. And very few of them have been adequately tested for safety.” Continue reading →
CORVALLIS, Ore. – Researchers at Oregon State University have discovered novel compounds produced by certain types of chemical reactions – such as those found in vehicle exhaust or grilling meat – that are hundreds of times more mutagenic than their parent compounds which are known carcinogens.
These compounds were not previously known to exist, and raise additional concerns about the health impacts of heavily-polluted urban air or dietary exposure. It’s not yet been determined in what level the compounds might be present, and no health standards now exist for them.
The compounds were identified in laboratory experiments that mimic the type of conditions which might be found from the combustion and exhaust in cars and trucks, or the grilling of meat over a flame.
“Some of the compounds that we’ve discovered are far more mutagenic than we previously understood, and may exist in the environment as a result of heavy air pollution from vehicles or some types of food preparation,” said Staci Simonich, a professor of chemistry and toxicology in the OSU College of Agricultural Sciences.
Dr. Staci Simonich, Project 5 Leader with the OSU Superfund Research Program
“We don’t know at this point what levels may be present, and will explore that in continued research,” she said.
The parent compounds involved in this research are polycyclic aromatic hydrocarbons, or PAHs, formed naturally as the result of almost any type of combustion, from a wood stove to an automobile engine, cigarette or a coal-fired power plant. Many PAHs, such as benzopyrene, are known to be carcinogenic, believed to be more of a health concern that has been appreciated in the past, and are the subject of extensive research at OSU and elsewhere around the world.
The PAHs can become even more of a problem when they chemically interact with nitrogen to become “nitrated,” or NPAHs, scientists say. The newly-discovered compounds are NPAHs that were unknown to this point.
This study found that the direct mutagenicity of the NPAHs with one nitrogen group can increase 6 to 432 times more than the parent compound. NPAHs based on two nitrogen groups can be 272 to 467 times more mutagenic. Mutagens are chemicals that can cause DNA damage in cells that in turn can cause cancer.
For technical reasons based on how the mutagenic assays are conducted, the researchers said these numbers may actually understate the increase in toxicity – it could be even higher.
These discoveries are an outgrowth of research on PAHs that was done by Simonich at the Beijing Summer Olympic Games in 2008, when extensive studies of urban air quality were conducted, in part, based on concerns about impacts on athletes and visitors to the games.
Beijing, like some other cities in Asia, has significant problems with air quality, and may be 10-50 times more polluted than some major urban areas in the U.S. with air concerns, such as the Los Angeles basin.
An agency of the World Health Organization announced last fall that it now considers outdoor air pollution, especially particulate matter, to be carcinogenic, and cause other health problems as well. PAHs are one of the types of pollutants found on particulate matter in air pollution that are of special concern.
Concerns about the heavy levels of air pollution from some Asian cities are sufficient that Simonich is doing monitoring on Oregon’s Mount Bachelor, a 9,065-foot mountain in the central Oregon Cascade Range. Researchers want to determine what levels of air pollution may be found there after traveling thousands of miles across the Pacific Ocean.
Today, NIEHS highlighted OSU SRC Trainee Andy Larkin from Project 1. Below is the spotlight from the SRP ePosted Notes.
Andy Larkin
Andy Larkin is working with David Williams and William Baird at OSU and just started his fourth year as a Ph.D. student. Larkin is doing great work and we look forward to his presentation on atmospheric pollutant models and smartphones in an upcoming Risk e Learning webinar.
Larkin’s Ph.D. research involves several different projects, all of which are designed to bridge the gap between basic research and risk assessment. Larkin is working on computational modeling for predicting biological responses to PAH mixtures, real time forecasts of atmospheric PM2.5, PM10, and ozone for the state of Oregon, and smartphone programs to predict and prevent atmospheric pollutant exposures.
While he has won an impressive seven awards* as a graduate student, he was most proud of winning second place in the Oregon State three-minute thesis competition. Although not the most prestigious of his awards, Larkin explains that, “Creating a summary of a thesis designed to be understood by the public and less than three minutes in length was by far the most challenging presentation of my graduate studies, and it was thoroughly rewarding to have so many members of the general public understand and enjoy the presentation.”
When he isn’t busy working on his outstanding graduate research projects, he enjoys community volunteer work and ultramarathon running. Larkin just ran the Portland Marathon on October 6 and his next ultramarathon is the Florida Keys 100 mile run in May!
After Larkin finishes his Ph.D., he hopes to work for a research group or regulatory agency to develop technologies for reporting real-time risk assessment and risk communication information. He also hopes these technologies will help to prevent unwanted exposures in sensitive populations.
*Note: The Training Core web site shares more specifics about Larkin’s recent awards.
Robert Tanguay, PhD (Project 3 ) focuses on examining the effects of selected chemicals and chemical classes on zebrafish development and associated gene expression pathways.
The Tanguay research group recently collaborated with Terrence J. Collins, PhD, a champion in the field of green chemistry at Carnegie Mellon University.
Collins and his collaborators showed that specific green chemicals (a group of molecules called TAML activators) used with hydrogen peroxide, can effectively remove steroid hormones from water after just one treatment. Steroid hormones are common endocrine disruptors found in almost 25 percent of streams, rivers, and lakes. Collins needed to understand the safety of TAML activators to move forward on this problem.
Tanguay’s group exposed zebrafish embryos to seven different types of TAML activators. None of the TAML’s impaired embryo development at concentrations typically used for decontaminating water.
The collaboration resulted in a new journal publication in Green Chemistry.
These are important findings that contribute toward TAML activators getting commercialized for water treatment.
Endocrine disruptors and human health
Endocrine disruptors can disrupt normal functions of the endocrine system and impair development, by mimicking or blocking the activities of hormones in wildlife. Several animal studies suggest that endocrine disruptors can also affect human health, and may be involved in cancers, learning disabilities, obesity, and immune and reproductive system disorders.
Robert Tanguay’s leadership in utilizing zebrafish
In 2012, Dr. Tanguay received an EPA grant award, “Toxicity Screening with Zebrafish Assay”. The award is for three years and almost two million dollars in funding to examine the developmental toxicology of at least 1000 chemicals.
Dr. Tanguay and his research team have tested over 3,000 compounds of interest to the National Toxicology Program (NTP), to complement the ongoing high-throughput screening efforts in the U.S. government’s multiagency Tox21 research program.
Citation:Truong L, DeNardo MA, Kundu S, Collins TJ, Tanguay RL. 2013. Zebrafish assays as developmental toxicity indicators in the green design of TAML oxidation catalysts. Green Chem; doi:10.1039/C3GC40376A [Online 15 July 2013].
