Chemicals associated with E-Cigarettes

Electronic cigarette is also referred as e-cig or e-cigarette, which is a battery-powered vaporizer which has a similar feel to tobacco smoking.

Third generation of e-cigarette that have organic light-emitting diode displays and buttons to adjust wattage or voltage.

Credit: Shutterstock/C&EN

Electronic cigarettes do not contain tobacco, although they do use nicotine from tobacco plants. They do not produce cigarette smoke but rather an aerosol. In general, they have a heating element that atomizes a liquid solution known as e-liquid.  E-liquid, also referred as e-juice or simply "juice", is a liquid solution that when heated by an atomizer produces vapor. The main ingredients of e-liquids are usually a mix of
propylene glycol (PG),

glycerin (G)

and/or polyethylene glycol 400 (PEG400),

sometimes with differing levels of alcohol mixed with concentrated or extracted flavourings;

E-cigarette fluid or “e-juice” comes in thousands of flavors, including pineapple custard and Scooby snack.

Credit: Associated Press

and optionally, a variable concentration of tobacco-derived nicotine.ingredients but without nicotine.

The solution is often sold in bottles or pre-filled disposable cartridges, or as a kit for consumers to make their own eJuices. Components are also available to modify or boost their flavour, nicotine strength, or concentration of e-liquid. Pre-made e-liquids are manufactured with various tobacco, fruit, and other flavors, as well as variable nicotine concentrations (including nicotine-free versions). Surveys suggested that the most liked e-liquids had a nicotine content of 18 mg/ml, and largely the favorite flavors were tobacco, mint and fruit. The flavorings may be natural or artificial.

Flavoring substances not identified in a natural product intended for human consumption, whether or not the product is processed. These are typically produced by fractional distillation and additional chemical manipulation of naturally sourced chemicals, crude oil or coal tar.

Most artificial flavors are specific and often complex mixtures of singular naturally occurring flavor compounds combined together to either imitate or enhance a natural flavor. These mixtures are formulated by flavorists to give a food product a unique flavor and to maintain flavor consistency between different product batches or after recipe changes. The list of known flavoring agents includes thousands of molecular compounds, and the flavor chemist (flavorist) can often mix these together to produce many of the common flavors.

Chemical	Odor
Diacetyl	Buttery
Isoamyl acetate	Banana
Benzaldehyde	Bitter almond
Cinnamaldehyde	Cinnamon
Ethyl propionate	Fruity
Methyl anthranilate	Grape
Limonene	Orange
Ethyl decadienoate	Pear
Allyl hexanoate	Pineapple
Ethyl maltol	Sugar, Cotton candy
Ethylvanillin	Vanilla
Methyl salicylate	Wintergreen

References and more to read:
http://cen.acs.org/articles/93/i7/Boom-E-Cigarettes-Sparks-Calls.html
http://en.wikipedia.org/wiki/Electronic_cigarette#Atomizer
http://health.howstuffworks.com/wellness/smoking-cessation/10-facts-about-e-cigarettes.htm
http://en.wikipedia.org/wiki/Flavor

Chemicals used for vector control

DDT has been used in malaria vector control because of its long residual efficacy when sprayed on walls and ceilings (6–12 months depending on dosage and nature of substrate).

Vector control is a method to limit or eradicate the mammals, birds, insects or other arthropods which transmit disease pathogens. The most frequent type of vector control is mosquito control using a variety of strategies.

DDT has been listed in the Stockholm Convention for persistent organic pollutants for international control. Recognizing that total elimination in many malaria-prone countries is currently unfeasible because there are few affordable or effective alternatives, the convention exempts public health use within World Health Organization (WHO) guidelines from the ban.

Today, about 3,000 to 4,000 tonnes of DDT are produced each year for vector control. DDT is applied to the inside walls of homes to kill or repel mosquitoes. This intervention, called indoor residual spraying (IRS), greatly reduces environmental damage. It also reduces the incidence of DDT resistance.

DDT (dichlorodiphenyltrichloroethane)

Reference
http://www.chem.unep.ch/DDT/documents/WHO_FAQonDDT.pdf
http://whqlibdoc.who.int/hq/2011/WHO_HTM_GMP_2011_eng.pdf
http://en.wikipedia.org/wiki/DDT
http://www.epa.gov/airquality/community/details/i-pesticides.html

Polychlorinated biphenyls (PCBs) in silicone-based adhesives and chlorophenylsilanes

Chlorophenylsilanes are the intermediate substances in the manufacturing of phenyl silicones. As suggested by evidence found in a recent study by Katsunori Anezaki,Takeshi Nakano, 
polychlorinated biphenyls (PCBs) could be formed along with reactions to synthesize
phenyl silicone.

Silicones are typically heat-resistant and rubber-like, and are used in sealants, adhesives, lubricants, medicine, cooking utensils, and thermal and electrical insulation. Some common forms include silicone oil, silicone grease, silicone rubber, silicone resin, and silicone caulk. Compared to methyl-based silicones, phenyl-based silicones have higher oxidation resistance, thermal stability and shear resistance. At elevated temperatures, phenyl-based silicones are more stable and resistant to thermal and oxidizing attack.

UN Calls for Wastewater Focus

In my research, I focus on toxic chemicals that cannot be removed from wastewater treatment. And a lot of studies aim to develop advanced wastewater treatment technologies to remove more toxic chemicals in order to reduce loadings of toxic chemicals to the environment, which would affect ecosystems and in turn human health.

While developed countries such as Canada and the USA have over 90% of wastewater treated, sanitation of wastewater is still a big challenge faced by many low-income countries.  The global data indicate that only 20% of global wastewater is currently being treated. Wastewater in some developing countries is barely treated before released to the environment. Low-income countries possessing only 8 per cent of the required capacity to treat wastewater effectively. Such untreated wastewater is likely to contaminate water supplies and cause diseases. A UN-Water Analytical Brief, produced by the World Health Organization (WHO), the United Nations Environment Programme (UNEP) and UN-Habitat, on behalf of UN-Water, describes the damage being done to ecosystems and biodiversity as 'dire' and warns of the threat wastewater will increasingly pose to human health, economic activity, and water security if left unaddressed.

It is obvious that sustainable wastewater management will become a key task for the world to apply in the coming years.

UN and WHO officials pointed out  "Wastewater management has been neglected in the rush to commercialize drinking water production, a situation exacerbated by a fragmented water management system in many countries, and the use of different technologies that are often designed separately and retrofitted to existing systems."

"Around 70 per cent of industrial discharge in developing countries goes untreated. And eutrophication - from wastewater and agricultural run-off - has, according to recent estimates, reduced biodiversity in rivers, lakes and wetlands by about one-third globally."

"It is time to turn this environmental and human health challenge into an opportunity. Agriculture consumes 70 per cent of global water withdrawal, but agricultural irrigation from reclaimed wastewater is on the rise, and is being used to irrigate 20 to 45 million hectares worldwide. This is just a fraction of what is possible if policy and available technologies converge to ensure that wastewater and water quality are fully integrated into a more holistic water agenda as part of the post-2015 process,"

"To be successful and sustainable, wastewater management must be an integral part of the critical levers of urban planning and legislation resulting in productive, healthy and livable cities. The upcoming UN Conference on Housing and Sustainable Urban Development, Habitat III, will be an opportunity to underscore the importance of effective wastewater management and highlight the role of wastewater in the new urban agenda."

References and read more:
www.unwater.org/publications/publications-detail/en/c/275896/
http://www.unep.org/newscentre/Default.aspx?DocumentID=2818&ArticleID=11130&l=en#sthash.KH72aIVy.dpuf

Health Risks from Inhaled Polychlorinated Biphenyls

Evaluating Health Risks from Inhaled Polychlorinated Biphenyls: Research Needs for Addressing Uncertainty

A recent article published in Environ Health Perspect by Lehmann et al. DOI:10.1289/ehp.1408564 describes some common sources of PCBs in indoor air and estimate the contribution of inhalation exposure to total PCB exposure for select age groups and identified some critical areas of research needed to improve assessment of exposure and exposure response for inhaled PCBs.

Air concentrations of polychlorinated biphenyls (PCBs) in some buildings can be orders of magnitude higher than background levels. The potential health risk posed by PCBs from indoor environment need to be assessed. To assess such risk we need to face some uncertainty.

Previous assessments of exposure and risk associated with PCBs primarily focused on dietary intake of contaminated food. With many recent studies suggested the importance of indoor PCB exposure, this article points out one important uncertainty for risk assessment of PCBs from indoor exposure.

The distributions of  PCB congeners in food and in indoor air are quite different. As such, toxicity of of PCB mixtures from indoor environment is likely to be different from toxicity due to dietary intake.

In addition to the uncertainty mentioned in the article, I think another uncertainty we need to face lies in the pathway from external exposure to internal exposure. Bioavailability/toxicokinetics of PCBs from inhalation would be quite different from dietary intake and need to be addressed.

Roles of the human occupant in indoor chemistry

"Human occupants, through the reactive chemicals that they emit, have a large influence on
the atmospheric chemistry that occurs around them, ultimately impacting their own chemical
exposures and their health" --A recent article published in the journal Indoor Air by Charles J. Weschler from the Environmental and Occupational Health Sciences Institute, Rutgers University gives an overview on roles of the human occupant in indoor chemistry.

As summarized by Weschler, a number of evidences suggested that there are pronounced influences of humans on chemistry within the indoor spaces they inhabit.

Occupants leave behind skin flakes, skin oils and body effluents on indoor surfaces and on their clothing. These human generated long-chain hydrocarbon involve unsaturated carbon bonds, which will react with indoor ozone and thus affect indoor chemical reactions involving ozone.

This review article also summarized the potential role of occupants on the levels of semivolatile organic compounds from indoor sources, which is based on a human uptake and exposure model coupled with an indoor chemical fate mass balance model that suggests human intake and elimination of a chemical (e.g., biotransformation, renal excretion, fecal egestion, hand washing, bathing)
influences its fate indoors. Such an impact varies according to chemicals properties (volatility, degradation, etc) as well as environmental characteristic (e.g., ventilation) and human behaviors (e.g. the frequency of cleaning. As mentioned by Wescler, this is an area that is potentially rich
for further exploration. Refer to this modeling study for more information.

Some facts summarized in the article:

• lipids on skin surface of human are a combination of sebum secreted by sebaceous glands and lesser amounts of lipids from the stratum corneum
• The chemicals that constitute skin surface lipids include triacyl glycerols (~25%), unesterfied fatty acids (~25%), wax esters (~22%), squalene (~10%), mono- and diacyl glycerols (~10%) and lesser amounts of sterol esters, sterols, phospholipids and other species 
• squalene is responsible for roughly 50% of the unsaturated carbon bonds in skin surface lipids

Finally, the review article by Weschler provides a summary on the roles of the human occupant in indoor chemistry- "We have read the early pages of what promises to be a long and interesting book –interesting, in part, because the subject is us. This unfolding story promises to inform strategies designed to protect our health, our technical devices and our cultural artifacts"

References and more to read: 

http://dx.doi.org/10.1111/ina.12185

http://dx.doi.org/10.1021/es502718k

$$$ saving is not the most motivative way to get people to save energy

What's the best way to persuade people to save energy or choose energy saving products ?  We might think it is by calculating how much money can be saved. 

But according to a recent study on incentives and energy conservation by Asensioa and Delmas at UCLA, today's U.S. electricity prices (averaging 13 cents per kilowatt hour nationally) the amount of money consumers could save by cutting energy isn't high enough to be motivating. Reminders of the environmental health benefits of cutting electricity use are far more powerful motivation.

The study was conducted by installing smart meters and appliance-level monitoring technology in the homes of about 120 young Los Angeles couples and families in the randomized, controlled experiment. The households were sent weekly e-mails to test the power of different motivational messages.

The group that received reminders of how much money they could save by cutting back on electricity showed no net energy savings over the four-month trial. But a similar group cut energy use 8 percent after receiving e-mails about the amount of pollution they were producing, and how it has been shown to cause childhood asthma and cancer. The health message was most effective in the subset of households with children at home

The health effects of ambient air pollution from coal and natural gas-burning, the fuels that generate most of the world's electricity. Global health damage estimates already exceed $120 billion, as noted in the study.

References and more to read: 
http://www.pnas.org/content/early/2015/01/07/1401880112
http://www.dailyclimate.org/tdc-newsroom/2015/01/energy-savings-health-benefits

Idling vehicle for a few minutes before driving in winter turns out to be WRONG

A driver used to park outside our office were always leaving his truck idling for quite a few minutes before he drove away. During this period, we had strong smell of gasoline in our office. Fortunately, this issue was solved by environmental safety & health so people in the office no longer suffer from toxic gas exposure.  After that, it is worthwhile for us to scrutinize the habit of leaving vehicle idle for a while before starting driving.

It is probably most people's idea that in winter, your car needs a little time to warm up before you can drive it. And that's why the driver used to park outside of my office often fire up their engines long before they start driving. With remote control, people might even start the car before leaving the office.

But this idea of idling your car during the winter turns out to be wrong! 

Before looking at why it is wrong, let's look at what is true and how people start from the truth and reach something wrong.

It is true that cars get worse fuel economy when it's really cold out -- they are at least 10% percent less fuel efficient and it takes longer for the engine to warm up and reach an optimal driving temperature in cold weather. Moreover, older cars that rely on carburetors as a crucial engine component  do need to warm up to work well. Without warming up, the carburetor would not necessarily be able to get the right mix of air and fuel in the engine.

During the 1980s and into the early 1990s, however, the auto industry did away with carburetors in favor of electronic fuel injection, which uses sensors to supply fuel to the engine and get the right air and fuel mix. This makes the problem of warming up the car before driving irrelevant, because the sensors monitor and adjust to temperature conditions.

Therefore, contrary to popular belief, excessive idling is not an effective way to warm up your vehicle, even in cold weather. The engine will warm up faster being driven. The best way to warm it up is to drive it. In fact, with today's computer-controlled engines, even on cold winter days, you should warm up the car no more than 30 seconds before you start driving  – but make sure that windows are free from snow and properly defrosted before driving away!  So idling does nothing for your vehicle.

But it does have several big (and avoidable) costs: 

1) Idling increases the amount of vehicle exhaust in our air. Exhaust contains many pollutants such as volatile organic compounds (VOCs), carbon monoxide (CO) and oxides of nitrogen (NOX) that contribute to air pollution and smog are linked to asthma and other lung diseases, allergies, heart disease,increased risk of infections and cancer and other health problems (that's why the environmental safety and health committee takes actions right after we report the issue).

2) An operating vehicle emits a range of gases from its tailpipe into the atmosphere, one of which is carbon dioxide CO2– the principal greenhouse gas that contributes to climate change. For every litre of gasoline used, a vehicle produces about 2.3 kilograms2 of CO2. With internal combustion engines, no technology exists for eliminating CO2 emissions, an unavoidable by-product of burning fossil fuels. One simple and effective way to reduce the production of CO2 emissions from light-duty vehicles is by choosing to eliminate unnecessary vehicle idling. This is an action that you – as a driver – can take.

3) Idling wastes fuel and money. An idling car uses between 1/5 to 7/10 of a gallon of fuel an hour. An idling diesel truck burn approximately one gallon of fuel an hour. Idling for a few minutes everyday can cost you several dollars per week – which doesn’t seem like much, but adds up in the long run


For people who are used to idle the car, welcome to use

Individual Idling Impact Calculator

and calculate the potential impact that you and your friends would have if you reduced unnecessary vehicle idling.

Some interesting fact about idling:

• The amount of idling a driver does tends to increase with the number of people in the household. 
• A driver living with children is more likely to idle than one without children. 
• The frequency of idling appears to decrease as a person ages – a retiree is the least likely to idle. 
• A person living in a rural area is more likely to idle than a driver living in an urban centre. 

References and more to read: 

• http://www.nrcan.gc.ca/energy/efficiency/communities-infrastructure/transportation/idling/4397
• http://www.washingtonpost.com/blogs/wonkblog/wp/2014/12/29/the-biggest-winter-energy-myth-that-you-need-to-idle-your-car-before-driving/
• http://www.ema-online.org/everything-you-need-to-know-about-idling

Delhi matches Beijing for air pollution threatening public health

Along with President Obama's state visit to India yesterday,  a number of news articles came with titles like "Obama is breathing world’s dirtiest air in New Delhi".

Such statement is presumably based on atmospheric particulate matter, which has impacts on climate and human health. Atmospheric aerosols affect the climate of the earth by changing the amount of incoming solar radiation and outgoing terrestrial long wave radiation retained in the earth's system. Particles smaller than 2.5 micrometers or PM2.5, tend to penetrate into the gas exchange regions of the lung (alveolus), and very small particles (< 100 nanometers) may pass through the lungs to affect other organs. Exposure of PM is associated with health effects such as asthma, lung cancer, cardiovascular disease, respiratory diseases, premature delivery, birth defects, and premature death.

In 2014, World Health Organization study finds Indian capital had dirtiest atmosphere of 1,600 cities around the world for PM2.5 particles. See the WHO Ambient (outdoor) air pollution database 2014 available at http://www.who.int/phe/health_topics/outdoorair/databases/cities/en/ and embedded below

Environment is one of the focuses during Obama’s India trip . Following the agreement in November with Chinese President for both countries to limit or cut carbon emissions, Obama is expected to meet with Indian Prime Minister to discuss topics such as educe greenhouse gas emissions and boost clean energy production. Currently, India heavily relies on fossil fuels as energy source, which has transformed New Delhi into the planet’s most polluted capital and made India the third biggest national emitter of greenhouse gases.

References and more to read: 

http://www.theguardian.com/world/2014/may/08/india-admits-delhi-matches-beijing-air-polllution-world-health-organisation-cities

http://globalnews.ca/news/1789010/obama-to-breathe-worlds-dirtiest-air-amid-climate-talks-in-new-delhi/

Flame retardant-polybrominated diphenyl ethers

Polybrominated diphenyl ethers or PBDEs, are used as flame retardant in a wide array of products, including building materials, electronics, furnishings, motor vehicles, airplanes, plastics, polyurethane foams, and textiles. They are structurally akin to the PCBs and other polyhalogenated compounds, consisting of two halogenated aromatic rings.

PBDEs bioaccumulate in blood, breast milk, and fat tissues. Bioaccumulation is of particular concern in such instances, especially for personnel in recycling and repair plants of PBDE-containing products.

photo source: http://www.greenpeace.org/international/en/campaigns/detox/electronics/


People are also exposed to these chemicals in their domestic environment because of their prevalence in common household items.  PBDEs have been found in common foods such as salmon, ground beef, butter, and cheese and also in indoor dust, sewage sludge, and effluents from wastewater treatment plants.

There is also growing concern that PBDEs share the environmental long life and bioaccumulation properties of polychlorinated dibenzodioxins. With levels found in households, PBDEs could reduce fertility in humans. Because of their toxicity and persistence, the industrial production of some PBDEs is restricted under the Stockholm Convention, a treaty to control and phase out major persistent organic pollutants (POPs).

Despite of the regulations,  there is still huge amount of PBDEs in products in use.
A recent study has estimated 60% of the stock of PBDEs (most Deca-Mixture) in 2014 will remain in the use phase in 2020. Such estimation considers only the first use (no reuse and/or storage) of PBDE-containing products. Additional PBDEs will be in the use phase in the future via reuse of PBDE containing material.

For more information in PBDE stock and emissions, read this article recently published in Environmental Science & Technology