Navigation Links
Case Western Reserve researchers looking at light-induced toxins in air and water

Is the air we breathe on a daily basis slowly killing us?

It may not be that severe, but the air we breathe and water we drink may be more harmful than we realize.

Toxic nitro-aromatic pollutants (or nitro-polycyclic aromatic hydrocarbons), both manmade and naturally occurring, continue to be emitted into the air and are present in food, water systems, soils and sediments, says Carlos Crespo, the Case Western Reserve University chemistry assistant professor whose research team is studying how ultraviolet-visible light interacts with and transforms these compounds under controlled laboratory settings.

The goal of his group is to assess the physical and chemical consequences of sunlight absorption by these pollutants in the environment. In particular, the Crespo research group wants to know the relaxation pathways used by these pollutants to redistribute the excess electronic energy gained when they absorb light and how this energy is used to transform these compounds into other harmful compounds or products. Their work is being funded by a $100,000 grant from the American Chemical Society Petroleum Research Fund.

"Degradation by sunlight is thought to be the main route of natural removal of nitro-aromatic compounds from the environment. Consequently, understanding how the absorption of light transforms these compounds holds the key for predicting their environmental fate and for designing effective pollution control strategies," says Crespo.

He added, "These relatively small compounds are formed primarily through incomplete combustion processes, like municipal incinerators, motor vehicles and power plants."

While these compounds do occur naturally in the environment, through actions like volcanic eruptions or forest fires, the use of fossil fuels increases the amount emitted into the atmosphere, increasing exposure to their harmful effects.

"Epidemiological studies show that exposure to diesel exhaust and urban air pollution is associated with an increased risk of lung cancer," Crespo says, noting that laboratory mammals and in vitro tests have found the compounds to be toxic, mutagenic and even carcinogenic.

Previous research works have shown that light-induced degradation of a number of nitro-aromatic compounds leads to products that are more toxic than their parent compounds. Further evidence suggests that these pollutants contribute as much as 10% of the total mutagenicity of inhalable, suspended particles in polluted areas. However, the specific pathways through which these compounds are transformed into products by sunlight are not well understood.

The Crespo group expects that by using sophisticated laser techniques with less than a trillionth of a second time resolution, in combination with computations based on quantum mechanical theories, a better understanding of the fundamental processes controlling the light-induced transformation of these pollutants can be obtained.

"Once we understand the physico-chemical factors that control the degradation of these compounds by light absorption at the molecular level, we might be able to use this knowledge to reduce some of these chemical transformations."

It is known that these compounds can release a nitric oxide (NO) radical when exposed to light. Crespo says one of the long-term goals of this research is to harness the power of these radical compounds for biological applications.

"Once we understand the factors that control the release of NO radicals, we could envision the use nitro-aromatic compounds as light-triggered, time- and site-controlled NO radical donors for therapeutic applications," he says. "But we are currently a long way from that."

Their 2008 paper, "Environmental Photochemistry of Nitro-PAHs: Direct Observation of Ultrafast Intersystem Crossing in 1-Nitropyrene," was one of the first scholarly works using femtosecond laser techniques (1 femtosecond = 1  10-15 seconds) to investigate the electronic energy relaxation pathways of these environmental pollutants. However it is an area that is gaining more interest.

"There have been several additional articles since, including one our group submitted this past December," Crespo says. "Research in this subject is getting competitive, but positive competition is great for science. "

His group is also focused in studying the light-induced ultrafast relaxation pathways in other relevant bio-organic compounds.


Contact: Jason A. Tirotta
Case Western Reserve University

Related biology news :

1. UT Southwestern researchers disrupt biochemical system involved in cancer, degenerative disease
2. Natural brain substance blocks weight gain in mice, UT Southwestern researchers discover
3. Climate changes impact on invasive plants in Western US may create restoration opportunities
4. Tree deaths have doubled across the western US
5. Study finds MRSA in Midwestern swine, workers
6. UT Southwestern scientist honored among best in Texas research
7. Case Western Reserve finds mechanism underlying alt. splicing of premessenger RNA into messenger RNA
8. UT Southwestern researchers identify gene linked to inherited form of fatal lung disease
9. Deranged calcium signaling contributes to neurological disorder, UT Southwestern researchers find
10. Case Western Reserve University uncovers genetic basis for some birth defects
11. NSF grant to launch undergrads from Case Western Reserve into math and science teaching
Post Your Comments:
(Date:10/8/2015)... , Oct. 8, 2015 Synaptics ... human interface solutions, announced today that it will ... fiscal 2016 on Thursday, October 22, 2015, after ... a corresponding conference call for analysts and investors ... which management may discuss forward-looking information.    ...
(Date:10/6/2015)... LAKE CITY , Oct. 6, 2015 ... company, announced today that it has signed a contract ... monitoring services across the full range of sentences under ... Group,s President of the Americas. "This contract with the ... region of the US and advances our position as ...
(Date:9/30/2015)...  With nearly 300,000 Americans living with spinal cord ... to reach 12,500 annually, the role of Independent Living ... Independent Living (SCRS-IL) is increasingly important. SCRS-IL is ... opening doors to independence for individuals with SCIs ... assistive technology services and education. "In serving ...
Breaking Biology News(10 mins):
(Date:10/9/2015)... 2015 On October 8, the Honorable Doris ... statement recognizing the third annual International Plasma Awareness Week ... by the Plasma Protein Therapeutics Association (PPTA) ... , Raise global awareness about plasma donation ... and improving lives , Increase understanding about lifesaving ...
(Date:10/9/2015)... SAN DIEGO , Oct. 9, 2015  DePuy ... ® Flex with Q-PACK ®  Technology**, the ... use in trauma-related extremity procedures (foot and ankle, hand ... The announcement was made here at the 2015 Orthopaedic ... (provides a natural scaffold for new bone growth) ...
(Date:10/9/2015)... San Francisco, CA (PRWEB) , ... October 09, 2015 , ... ... with a study that aims to better understand the relationship between weight management and ... more frequently and more accurately from participants using an iPhone app. , The uBiome ...
(Date:10/8/2015)... 8, 2015  Sorrento Therapeutics, Inc. (NASDAQ:  SRNE; ... for cancer and associated pain, announced today that Dr. Henry ... presenting at the Aegis Capital Corporation 2015 Growth ... Capital Corporation 2015 Growth ConferenceDate:Friday, October 9, 2015Time:10:00 ... @ The Wynn in Las Vegas, NV , ...
Breaking Biology Technology: