Environmental Science: Processes & Impacts blog

Amines are (usually smelly) organic compounds that contain a basic nitrogen atom bearing a lone electron pair. They are often used in solvents and reagents, which causes them to be released to the atmosphere. Atmospheric amines may be dangerous for several reasons;

• Oxidation of amines can result in some highly carcinogenic compounds
• The release of amines to the air can alter the nitrogen cycle
• Amines can contribute to chemical processes, including nucleation and the formation of aerosols, which can affect the water cycle by generating rain in unexpected locations

Structure of ethylamine (image by @moleculd, http://twitter.com/moleculd)

Thus, it is important that we can rely on effective ways of measuring the concentration of amines in the atmosphere. In this paper developed by chemists and engineers at Fudan University in Shanghai, China, the authors optimize a new quantitative analysis of aliphatic amines found in urban samples. To do so, these researchers have created a novel on-line derivatization of amines that transforms them into highly fluorescent molecules that can be separated and analyzed by HPLC.

This new method simplifies the experimental efforts normally required by offline derivatizations. The authors also demonstrated, using different concentrations of certified standards, that the method is statistically accurate. In addition, the procedure is very sensitive, reaching detection limits of 1 microgram per liter (ppb) for all the aliphatic amines that were analyzed.

Pollution over Shanghai (picture by Peter Dowley, https://www.flickr.com/people/40271931@N00)

Finally, it is worth highlighting that, using their own novel method, the authors have been the first to detect and quantify the seasonal variation of aliphatic amines in the pollution-fog over Shanghai. They have proved that these organic molecules are more abundant during the summer. Could this have any implications on local weather?

Interested in this research? Click on the link below to read the full article for free*

Quantitative analysis of aliphatic amines in urban aerosols based on online derivatization and high performance liquid chromatography.
X. Huang, C. Deng, G. Zhuang, J. Lin, and M. Xiao.
Environ. Sci.: Processes Impacts, 2016, Advance Article
DOI: 10.1039/C6EM00197A

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About the webwriter

Fernando Gomollón-Bel is a PhD Student at the ISQCH (CSIC–University of Zaragoza). His research focuses on asymmetric organic synthesis using sugars as chiral-pool starting materials towards the production of fungical transglycosidase inhibitors.

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*Access is free until 12/07/2016 through a registered publishing personal account.

Most of the materials we use nowadays are impregnated with several chemicals to make them fireproof and meet fire safety regulations. These are classically halogenated compounds such as polybrominated diphenyl ethers (PBDEs). Recently, the food safety authorities in the EU banned PBDEs because several studies linked them to hepatic damage and perturbations in metabolism.

Environ. Sci.: Processes Impacts

Hence, chemists developed a new kind of fire retardants known as hexabromocyclododecanes (HBCDs). Manufacturers of goods such as plastics, textiles and electronic equipment, are increasingly using these compounds. However, HBCDs may not be an ideal solution: recent studies found them in dust, air, sediments, and sewage in areas surrounding electronic waste (or e-waste) processing plants. And what is worse, the presence of HBCDs has also been reported in eggs, while researchers have confirmed human exposure from eating food sourced near the e-waste treatment plants. These are concerning issues, since these chemical are potentially toxic, persistent and bioaccumulative.

In this article published in Environmental Science: Processes & Impacts, Dr. Fang Tao and co-workers investigated the presence of HBCDs and other fire retardants in fish, pigs and free-range chickens reared in areas that could have been polluted by e-waste plants in Bui Dau, Vietnam. In addition to this, the team also took samples from supposedly non-contaminated zones both in Vietnam and Japan and analysed them.

The authors reported that HBCDs, as well as other emerging fire retardants, are found in chicken, fish and pork samples collected near the e-waste processing plant in Bui Dau. According to these data, locals may be ingesting dangerous amounts of toxic, accumulative chemicals. Although the dangers of some of these compounds are not completely defined yet, the researchers suggest to keep studying this phenomenon: the quantity of these contaminants in the environment may rise soon.

Interested in this research? Click on the link below to read the full article for free*

Emerging halogenated flame retardants and hexabromocyclododecanes in food samples from an e-waste processing area in Vietnam
Fang Tao, Hidenori Matsukami, Go Suzuki, Nguyen Minh Tue, Pham Hung Viet, Hidetaka Takigami and Stuart Harrad.
Environmental Science: Processes and Impacts, 2016, Advance Article
DOI: 10.1039/C5EM00593K

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About the webwriter

Fernando Gomollón-Bel is a PhD Student at the ISQCH (CSIC–University of Zaragoza). His research focuses on asymmetric organic synthesis using sugars as chiral-pool starting materials towards the production of fungical transglycosidase inhibitors.

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* Access is free until 11/04/2016 through a registered RSC account.

The (Mad) Hatter from Carroll's Alice in Wonderland (Illustration by John Tenniel - Public Domain)

The Hatter in Alice in Wonderland may not have been mad after all. He might have suffered from mercury poisoning! Thankfully, nowadays we know mercury is a dangerous element in almost all its forms. Organomercury compounds such as monomethylmercury (MMHg) and dimethylmercury (DMHg) are especially hazardous: not only because of their extreme toxicity but also because they can be bio-magnified in the food web. Moreover, mercury can travel the biosphere through air, water and soil, increasing the danger.

Even if we have stopped using mercury thermometers, a big number of household and industrial products still use this liquid metal. A lot of these products end up in landfills where they are treated as conventional waste, and may liberate dangerous amounts of this toxic metal to the atmosphere and soil.

In this critical review published in Environmental Science: Processes & Impacts, scientists analyze solid waste management in landfills and the chemistry of mercury, as well as the release of this metal into the environment and the possible bio and geological transformations it may suffer. As a conclusion, researchers review a series of studies that should be considered in depth in order to understand the problem of mercury release and to, eventually, find a solution.

As described in this work, landfills –mainly when they undergo the so-called anaerobic phase– present the ideal conditions (pH, redox, organic matter) for mercury to be speciated and transformed, then dissolved, mobilized and disseminated within the biosphere. It is mostly released as Hg(0) in gas form, but other species like MMHg and DMHg may also be produced and incorporated to soil and water reservoirs.

Whether you are a specialist in mercury or not, this review will surely captivate you. Landfills may seem boring, but the chemistry underneath is fascinating, like the liquid metal that fascinated alchemists for centuries. Remember, mercury was the prima materia from which all metals were formed!

Interested in this research? Click on the link below to read the full article for free*:

Biogeochemical transformations of mercury in solid waste landfills and pathways for release
Sung-Woo Lee, Gregory V. Lowry and Heileen Hsu-Kim.
Environmental Science: Processes & Impacts 2016, 18, 176-189
DOI: 10.139/C5EM00561B

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About the webwriter

Fernando Gomollón-Bel is a PhD Student at the ISQCH (CSIC–University of Zaragoza). His research focuses on asymmetric organic synthesis using sugars as chiral-pool starting materials towards the production of fungical transglycosidase inhibitors.

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* Access is free until 18/03/2016 through a registered RSC account.

Most petroleum hydrocarbons are dangerous for the environment and are known to be toxic. These chemicals can cause severe respiratory problems, mutations and cancer. A very particular type of hydrocarbons, known as polycyclic aromatic hydrocarbons (PAHs), represents a serious environmental threat. PAHs can obviously be dangerous when directly inhaled, but they are especially harmful since they can accumulate in water, sediments and soil, taking decades to decompose and thus polluting ecosystems for generations.

A few years ago, some scientists observed that certain species of bacteria had developed, by the means of natural selection, the ability to degrade molecules like hydrocarbons or polymers. Some of these species have evolved to degrade PAHs such as naphthalene, phenanthrene or pyrene, which means that they can be used to treat the waste of certain chemical plants, lowering the amount of these dangerous products released in to the environment.

Using tools like artificial selection or genetic engineering could enhance the efficacy of these bacteria. Moreover, the influence of some external factors may be optimized to improve the conversion of pollutants to non-toxic substances. In this article, recently published in Environmental Science: Processes & Impacts, Professor Mutai Bao and his team studied the effects of supporting bacteria on biodegradable, porous, low-cost materials like semi-coke, walnut shells and activated carbon. Immobilization methods are widely used and accepted by the scientific community because they are versatile and straightforward. Moreover, these systems can be easily cleaned and reused.

Before performing the experiment, scientists had to choose the right species of bacteria. They also had to let them adapt until they were able to properly digest PAHs. To facilitate this, bacteria were fed small amounts of classic carbon sources: glucose, lactose, starch or urea. The ones that received the combination of lactose and PAHs gave the best biodegradation results and were used for the optimization.

After a series of experiments, the authors concluded that immobilized bacteria degrade up to 47% more PAHs than free microbes. Semi-coke was the best support for these microorganisms, followed by walnut shell and activated carbon. In addition to this, they found bacteria to be adaptable to a broad range of pH and salinity. These biodegradation systems could be used in real-life situations such as oil spills in the ocean, where usually other techniques are less productive.

Interested in this research? Click on the link below to read the full article for free*

Biodegradation of different petroleum hydrocarbons by free and immobilized microbial consortia
Tiantian Shen, Yongrui Pi, Mutai Bao, Nana Xu, Yiming Li and Jinren Lu
Environ. Sci.: Processes Impacts, 2015, 17, 2022-2033
DOI: 10.1039/C5EM00318K

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About the webwriter

Fernando Gomollón-Bel is a PhD Student at the ISQCH (CSIC–University of Zaragoza). His research focuses on asymmetric organic synthesis using sugars as chiral-pool starting materials towards the production of fungical transglycosidase inhibitors.

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* Access is free until 18/02/2016 through a registered RSC account.

We have used nuclear energy for a while now. It is a clean form of energy, except for one little thing: what happens with radioactive waste? Scientists think the best solution is burying it deep in the ground and labelling it clearly enough so that future generations (or aliens!) will not dare to look inside. However, is this really the best solution? What happens with radioactive nuclei once they are inside the nuclear graveyard?

Scientists need to study the interactions of radioactive elements with the environment that surrounds them in the ground. But using radioactive elements is tricky: they can be dangerous and unstable, and most of them tend to decay in a few seconds (minutes, if you are lucky). Hence, researchers have determined to use models that mimic the behaviour of elements such as americium, curium or plutonium. Right in the row above actinides we find lanthanides, which have very similar oxidation states and comportment.

Source: Wikipedia.org

Scientists dig into europium. Not only because of its stability, but also because of its high fluorescence. This makes europium easy to track down in the lab. Outside the lab, europium is also very useful: the European Central Bank (ECB) uses europium as a fluorescent marker to fight counterfeit banknotes. Rumour has it the ECB intended the euro pun when choosing this particular element.

A group of researchers in China have studied the interactions of europium with alumina and humic acid (HA). These two substances represented the average inorganic and organic components of soil. In previous studies, they investigated the effect of reaction time, pH or ionic strength. In this paper, recently published in Environmental Science: Processes & Impacts, researchers examined the influence of temperature in the interactions of europium. And temperature is important when it comes to radioactive wastes: nuclear debris can keep temperatures of up to 100ºC during at least 1000 years, due to exothermic radioactive effects such as decomposition.

Luckily, the results were quite positive. Apparently, at high temperatures the formation of very stable structures is favoured, and the sorption of europium in alumina and alumina/HA systems is slightly increased with temperature. Nonetheless, trivalent cations are not the only substances present in nuclear waste. The interactions between soil-like substances (like alumina or HA) and other type of nuclei remain to be studied in depth.

Click on the link below to read the full article for free*

Sequestration and speciation of Eu(III) on gamma alumina: role of temperature and contact order
Yawen Cai, Xuemei Ren, Yue Lang, Zhiyong Liu, Pengfei Zong, Xiangke Wanga and Shitong Yang
Environ. Sci.: Processes Impacts, 2015, 17, 1904-1914
DOI: 10.1039/C5EM00412H

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About the webwriter

Fernando Gomollón-Bel is a PhD Student at the ISQCH (CSIC–University of Zaragoza). His research focuses on asymmetric organic synthesis using sugars as chiral-pool starting materials towards the production of fungical transglycosidase inhibitors.

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* Access is free until 20/12/2015 through a registered RSC account.

There are 200,000 cars fires every year in the United States. The number in the UK is even more impressive: 100,000 car fires every year (which means around 300 fires a day). Car fires are usually short, but also very intense, and release dangerous products that may not only pollute the environment, but also seriously affect the firemen tackling them. Despite the high incidence of this type of fires, very few studies have addressed the hazardous exposures firemen may be suffering.

The sampling platform used for "vacuuming" the fumes

Two researchers from Cincinnati (Ohio) have published a paper in Environmental Science: Processes & Impacts investigating the dangers of ultrafine and respirable particles released during vehicle fire suppression. They set three different cars on fire and asked a crew of firemen to suppress them with water. Meanwhile, a huge “vacuum cleaner”-like machine took samples that were later analysed by the two scientists.

The particle emissions were, like the fires, only present for a short period of time. However, the concentrations measured during the blaze were orders of magnitude bigger than the safe limits. They also found that cabin fire suppression is more dangerous than putting out just the engine compartment. The explanation might be simple: when the whole cabin is burning down, there is more fuel feeding the combustion, leading to more emissions and longer extinction times.

Another key aspect to consider is wind. Usually fire crews are trained to position themselves in an upwind and smoke-free spot, but you can’t control wind. When wind veered, particle emissions went off the chart, consequently increasing the risks.

Further studies will be carried out. In the meantime, the authors conclude that a self-contained breathing apparatus (a mask that works with compressed air generating a positive pressure inside it) should be worn throughout all the phases of extinguishing a vehicle fire. Otherwise, the hazardous vapours and particles released to the atmosphere may increase the risk of cancer in firemen.

Click on the link below to read the full article for free*

Ultrafine and respirable particle exposure during vehicle fire suppression
Douglas E. Evans and Kenneth W. Fent
Environ. Sci.: Processes Impacts, 2015, 17, 1749-1759
DOI: 10.1039/C5EM00233H

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About the webwriter

Fernando Gomollón-Bel is a PhD Student at the ISQCH (CSIC–University of Zaragoza). His research focuses on asymmetric organic synthesis using sugars as chiral-pool starting materials towards the production of fungical transglycosidase inhibitors.

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* Access is free through a registered RSC account.