A dangerous cocktail brews in our towns and cities- How tobacco smoke and vehicular emissions together contribute to wheezing in young children

Vehicular emissions and tobacco smoke are harming the lungs of young children  in our cities

When it comes to the evidence against tobacco and vehicular emissions on harming human respiratory health, it does not rain but it pours. And it keeps on coming. We have extensive evidence to show that vehicular emissions as well as tobacco smoke exposure are bad for health and it seems to start right from the fetal stage.  A new study presented in the journal Environmental Health shows that exposure to traffic-related air pollutants is associated with increased risks of wheezing in children who are exposed to tobacco smoke in fetal  life and infancy indicating an axis of villains who co-operate to exert their  harmful effects.

The study was a large prospective cohort study involving 4,634 children in Rotterdam, the second largest city in the Netherlands.  One of the largest ports in the world, it is also one of the most polluted places in the Netherlands and an apt location for pollution studies. A prospective cohort study is one that monitors a group of similar individuals –cohorts- who differ in certain factors under study over a time period in order to understand how these factors affect rates of a certain outcome- in this study, how effects of vehicular emissions, tobacco smoke exposure (in any stage starting from fetal life to the age of 3 years) affect wheezing in children.

Many cities, like this one, has air pollution monitors that helps scientist understand how air pollutants affect human health .

 Particulate matter (PM) of the size of 10 microns or less can penetrate the deepest part of the lungs such as the bronchioles or alveoli. Domestic coal combustion was once the major source of particulate emissions, but recently other sources such as road transport are important sources with diesel vehicles notably emitting increased levels. Road vehicle exhausts, off road equipment, and power plants  are  important sources of NO2.  In addition to contributing to the formation of ground-level ozone, and fine particle pollution, NO2 is linked with a number of adverse effects on the respiratory system. In this study, the exposure of children to particulate matter (PM10) and nitrogen dioxide (NO2) were assessed by analysing emission data at the home address. Parents were asked to fill questionnaires that indicated whether their children had wheezing until the age of 3 years.  Parents were also asked to provide information on whether the fetus or the baby had been exposed to tobacco smoke either through the mother or the partner smoking tobacco.

Results from the study indicated that average annual PM10 or NO2 exposure levels per year were not associated with wheezing in the same year.  Even though there were trends showing a link with PM10 or NO2 exposure levels and wheezing during the first 3 years of life, the results were not statistically significant. The researchers did not observe associations of traffic-related air pollutants with wheezing among children who were exposed to smoke during fetal life only or during infancy only. But in children who were exposed to tobacco smoke in both fetal and infant stage, PM10 or NO2 exposure levels was associated with wheezing during the first 3 years of life. The scientists did not observe associations of traffic-related air pollutants with wheezing among children who were not exposed to tobacco smoke.

There are limitations in the study, one of  which the researchers have noted viz. the possibility of ‘misclassification of air pollution assessment’ owing to the analysis only  involving  exposure levels at home addresses and not at the day care centers or other places where the child may spend days and nights. One factor that could have further added value to the study is blatantly missing- work addresses of mothers and PM 10, NO2 levels  - and whether when analysed together with air pollution exposure at home had any links to wheezing in children.

Nevertheless the study extends our understanding on how air pollution and tobacco smoke exposure contribute to the health of younger children. The  results suggest that long term exposure to traffic-related air pollutants is associated with increased risks of wheezing in children exposed to tobacco smoke in fetal life and infancy. Tobacco smoke exposure in early life might lead to increased vulnerability of the lungs to air pollution. The evidence appears to show that exposure of fetus and  infant lung to tobacco smoke primes it for damage by air pollutants leading to wheezing suggesting that the dangerous cocktail is made more potent by the ingredients together.

References

http://www.umwelt.nrw.de/umwelt/pdf/pronet/factsheets/16.pdf

Sonnenschein-van der Voort, A., de Kluizenaar, Y., Jaddoe, V., Gabriele, C., Raat, H., Moll, H., Hofman, A., Pierik, F., Miedema, H., de Jongste, J., & Duijts, L. (2012). Air pollution, fetal and infant tobacco smoke exposure, and wheezing in preschool children: a population-based prospective birth cohort Environmental Health, 11 (1) DOI: 10.1186/1476-069X-11-91

A matter of the heart

Some years ago, I accompanied a young relative, a very eager science graduate working on particulate matter, as she conducted her research survey on public perception of particulate matter and its effects in a certain borough of London. Particulate matter (PM) is used to describe solid matter suspended in a gas or liquid phase. In the environment, particulates may occur naturally (as consequence of forest fires, volcanoes, dust storm, sea sprays etc) or via anthropogenic activities, such as the burning of fossil fuels in automobile exhausts and other industrial processes. PM10 is used to describe particles of 10 micrometres or less. Unsurprisingly, densely populated metropolitan areas in developing countries are hot spots for PM. The exercise with my relative was an eye-opener, and also quite fun as we pounced on shoppers, city workers on lunch breaks, pedestrians in Central London etc., armed with our clip boards and ticking or crossing their responses. I enjoyed being the magician’s assistant….but that is another story.

All this came back to me as I read the recent article by Bhaskaran et al, of the London School of Tropical Medicine and Hygiene, who studied the effects of air pollution on the risk of heart attack- specifically whether alterations in pollution levels on an hourly timescale affects the short-term risk in urban settings of England and Wales, So what is the novelity in this study? The links between particular matter and heart and lung diseases is documented and there are several publications in these topics.In an earlier post in this site, David discussed a study where PM10 caused increase in blood pressure in traffic controllers in the metropolitan area of Sao Paolo. However, there is a wee difference in what this paper covered: This work considered the overall risk of heart attack in urban settings of England and Wales over very short time frames and it involved a large population size. In essence, this study looked at effects of very short-term exposure (which was not, previously possible due to technology limitations). In this mega-study of over 79000 individuals with a diagnosis of heart attack over three years from 15 cities( including Greater London, Greater Manchester, West Yorkshire, Bristol, Cardiff, Southampton) the team looked at PM10 and other pollutants such as ozone, carbon monoxide, nitrogen dioxide, and sulphur dioxide over five short periods of up to 72 hours. For the analysis of their results they used statistical modelling approach for single pollutant and multiple pollutants where they adjusted for factors that could influence and otherwise confuse data including ambient temperature, humidity, virus in the atmosphere ( both that for flu and for other infections- respiratory syncytial virus). The researchers found that increase in PM10 levels & NO2 levels was associated increase in risk for heart attacks 1-6 hours post-exposure;.The source of PM10 & NO2 in urban areas is largely from automobile exhausts. Interestingly the increase in immediate risks was followed by reduction in risks at longer lags and therefore they found no net risk increase over 72 hour periods. They found a protective effect for increase in CO & ozone however; there was no change in overall risk over 72 hours leading the team to speculate that ischaemic events that would have occurred soon were advanced by a few hours. Most studies so far had shown the effects after years of chronic exposure and herein lies the difference of this study. A previous small study in Greater Boston with less than 1000 subjects showed an increased risk 1-3 hours after exposure of PM10. The risk was 11% which is higher than that observed in the current study. What do the results mean cumulatively? Remember this was a statistical exercise, though a worthy one. It would still be interesting to explore the physiological, cellular, & molecular basis of organ responses to short-term exposure to PM10 which will further our understanding. It might also be interesting to pursue questions such as, are there individuals of a particular genetic signature who might be prone to the effects of short-term exposure and low doses of PM more than others? the effect of age etc. Are similar trends seen in respiratory disorders? Does PM exposure compound the effects in vulnerable populations? All these questions remain.

But what does the study mean to the society as a whole and what can we do? The results in addition to the existing body of evidence should send warning bells to the world but emerging economies that are mushrooming urban sprawls. The recent UN summit highlighted the importance of non-communicable diseases including cardiovascular disease on the global health. With NCDS (CVDS and cancer) accounting to 36 million of global deaths in 2008 WHO stats, the UN draft resolutionon (dated 16 September 2011) submitted by the President of the General Assembly - political declaration of the high level meeting of the general assembly on the prevention and control of non-communicable diseases -concedes the gravity of the situation and ‘recognizes that prevention must be the cornerstone of the global response to NCDS’ and identified several modifiable factors including diet and tobacco smoke that results in the rise of NCDS and called for ‘reducing their exposures’. These are valid and commendable. However, a glaring omission is the lack of mention of air pollutants contributing to NCDs. In the UN document, the closest air pollution is touched upon is with the reference to pollution from cooking stoves used for indoor cooking and heating. In essence, the enumerated risk factors do not include particulate matter from vehicles!!.

The results in this paper and the other background research cannot be ignored and should prompt usto push for measures for cutting down particulate matter emissions. Prevention is certainly a better option than treatment and cure as the UN draft declaration as well as common sense dictate. Importantly, prevention is something that is easy to achieve, but requires efforts starting from the individual to local to the global.

http://ecoratorio.blogspot.com/2011/08/stuck-in-traffic.html

http://www.ghd-net.org/negotiations/un-summit-non-communicable-diseases/official-documents

http://www.psr.org/environment-and-health/code-black/blog/regulating-killer-particulate-matter.html

Bhaskaran K, Hajat S, Armstrong B, Haines A, Herrett E, Wilkinson P, & Smeeth L (2011). The effects of hourly differences in air pollution on the risk of myocardial infarction: case crossover analysis of the MINAP database. BMJ (Clinical research ed.), 343 PMID: 21933824

Formula 1’s new green cloak

Formula 1’s (F1) foray into the carbon-reduction drives may not have exactly been a bombshell since it is in vogue to don a green cloak and hail this environmentally efficient attitude of reducing carbon footprint.

Trucost’s finds:
Trucost, an environmental consultancy, had conducted an exhaustive research on the full range of activities performed by and within F1 teams and their suppliers. Unsurprisingly, the carbon emissions arising from the testing and racing of F1 cars is only a small proportion (0.29%) of the total carbon chocked up by F1 as a whole (215,588 tonnes per annum in 2009, the majority being attributable to the production and supply of raw materials and parts at 50%, electricity consumption at 30%, as well as transport of team and equipment from race to race at 14%). Trucost’s environmental research analysis suggested measures to decrease carbon emissions- ergo, the Formula One Teams Association (FOTA, which comprises of all 12 current Formula One Teams) has commenced a comprehensive and externally audited carbon emissions reduction programme. It is anticipated (by Martin Whitmarch, Chairman of FOTA and Team Principal of Vodafone McLaren Mercedes) that F1 will have reduced its total carbon emissions by 12.4% compared with the 2009.

FOTA’s aims:
A small step, but some step nonetheless towards cutting the total carbon emissions of the sport. The ultimate stated aim is to address environmental problems and benefit mankind in the long run. This is to be achieved by developing new automotive technologies which may be, in time, introduced in consumer production cars. Consequently, from 2013, all entrants have to obey technical regulations, such as fitting the F1 cars with fuel efficient engines and powertrains. Furthermore, F1’s regulations will be revised to enhance and incentivise further reduction of fuel consumption and enhancement of fuel efficiency (apparently, the amount of fuel which can be used by each team could be restricted).

Therefore, the major sources of emissions reductions come from reduced electricity consumption (16.95%), reduced operational fuel use (17.92%), and reduced expenditure on parts and raw materials (20.25%).

Tips on reaching the chequered flag (apart from those stated by FOTA):

- As of yet, F1 held 19 races in 2010, around the world, and in no particular order- starting at Bahrain in March and ending at Abu Dhabi in November. As a result, there is a significant of zig-zagged travelling and carting of teams and equipment around the world, from race to race, by air, road, rail, and sea- not to overlook the devoted fans and spectators from around the world. So races could be conducted in a systematic manner, for instance, an itinerary which starts in Europe, then moves on to the Middle Eastern races at Abu Dhabi and Bahrain, and then the Asian races (Chinese, Malaysian, Singaporean, Japanese and Korean GP). Or a more austere option would be to conduct the races solely in one continent per annum.

- Decrease the number of teams.

- Alternatively, decrease the number of races.

- Imposing emissions cap on each team.

- Conducting a GP solely with green technology (this will also popularize such consumer cars).

- Use ethanol as fuel (examples being Australia’s V8 SuperCar series which uses 80% ethanol and Indy Racing which uses 100% ethanol). However, this opens a can of worms. Producing ethanol does require more energy input. Furthermore, there is an increased risk of deforestation (especially rainforests) so as to provide area for corn cultivation. If existing agricultural lands are utilised for biofuel cultivation, there could be an increase in food prices (and such affects the poor more detrimentally). A feasible solution is if biofuel is made from crop wastes or sourced by cultivation in wastelands.

- Use less(er) fuels. From my former days as an F1 fanatic, I seem to remember that teams were always keen on lesser fuel, for more fuel implies more weight, which implies slow(er) car, a veritable harakiri in a sport where every millisecond counts.

- The electricity used (also for lighting up the tracks) could be sourced from solar/wind/tidal- the former an excellent option in the Middle Eastern and Asian races.

- No more races held at night (I believe, this is the case at Singapore and Abu Dhabi).

- F1 is bound to consume a significant amount of water as well- therefore, rain water could be harvested for non-drinking purposes.

- Planting innumerable rows of trees around the F1 circuits- trees are, after all, carbon sinks.

- Creation of energy efficient and clean/green technologies (which could be translated to consumer cars), which also implies something akin to starting from scratch.

Force behind the force:
One of the drivers behind this step of FOTA is pressure from sponsors who are increasingly keen to be associated with a ‘green product’. So is it just green washing to smoothen ruffled feathers?

More likely is the possibility that this new green mantle is all thanks to new austerity measures, the consequence of the financial stress faced by F1 as a result of the recession.

My other two cents:
I would like to see how the earmarked 12.4% carbon emissions cut can be achieved.

Secondly, it does seem as if FOTA’s current plans/suggestions are targeting the measly 0.3% of emissions contributable to racing and testing of F1 cars. Shouldn’t the focus be placed on the remaining 99.7% of emissions and their sources?

Whilst teams such as Lotus and McLaren (the first to achieve a Carbon Trust certification for ‘achieving annual savings of more than 1500 tonnes of CO2 emissions) have whole-heartedly accepted the new rules, Ferrari’s disgruntled attitude towards the new cloak does make wonder whether this entire greening is a conscious change towards efficiency and environmental responsibility.

What also significantly irks me is that whilst F1 lays focus on carbon emissions, they are totally overlooking the pollutants, especially NOx and particulates (likely to be emitted from a myriad of sources, including F1 engines).

I wonder whether, as in a domino effect, F1’s new stance would inspire its fans to adopt an environmentally friendly outlook. And is it too much to hope that they wouldn’t be using petrol-based transportation to reach the race tracks? Hopefully, the future might be bright, but not be orange, but green.

Sources:

FOTA

Reuters

Image source: Pete Keen / Free Digital Photos.net