Prenatal Exposure to Airborne Polycyclic Aromatic Hydrocarbons and Children's Intelligence

September 3, 2010 · 0 comments

Environ Health Perspect. 2010 Sep;118(9):1326-31.

Prenatal Exposure to Airborne Polycyclic Aromatic Hydrocarbons and Children’s Intelligence at 5 Years of Age in a Prospective Cohort Study in Poland.

Edwards SC, Jedrychowski W, Butscher M, Camann D, Kieltyka A, Mroz E, Flak E, Li Z, Wang S, Rauh V, Perera F.

Columbia Center for Children’s Environmental Health, Mailman School of Public Health, Columbia University, New York, New York, USA.

Background: In this prospective cohort study of Caucasian mothers and children in Krakow, Poland, we evaluated the role of prenatal exposure to urban air pollutants in the pathogenesis of neurobehavioral disorders.

Objectives: The objective of this study was to investigate the relationship between prenatal polycyclic aromatic hydrocarbon (PAH) exposure and child intelligence at 5 years of age, controlling for potential confounders suspected to play a role in neurodevelopment.Methods: A cohort of pregnant, healthy, nonsmoking women was enrolled in Krakow, Poland, between 2001 and 2006. During pregnancy, participants were invited to complete a questionnaire and undergo 48-hr personal air monitoring to estimate their babies’ exposure, and to provide a blood sample and/or a cord blood sample at the time of delivery. Two hundred fourteen children were followed through 5 years of age, when their nonverbal reasoning ability was assessed using the Raven Coloured Progressive Matrices (RCPM).

Results: We found that higher (above the median of 17.96 ng/m3) prenatal exposure to airborne PAHs (range, 1.8-272.2 ng/m3) was associated with decreased RCPM scores at 5 years of age, after adjusting for potential confounding variables (n = 214). Further adjusting for maternal intelligence, lead, or dietary PAHs did not alter this association. The reduction in RCPM score associated with high airborne PAH exposure corresponded to an estimated average decrease of 3.8 IQ points.

Conclusions: These results suggest that prenatal exposure to airborne PAHs adversely affects children’s cognitive development by 5 years of age, with potential implications for school performance. They are consistent with a recent finding in a parallel cohort in New York City.

Editor’s Summary: Polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene, are released into ambient and indoor air from combustion sources (e.g., coal burning power plants, diesel and gasoline-powered vehicles, home heating and cooking) and are present in tobacco smoke and charred foods. Edwards et al. (p. 1326) studied the role of prenatal exposure to urban pollutants in the pathogenesis of neurobehavioral disorders in a prospective cohort study of Caucasian mothers and children in Krakow, Poland. The authors report that higher prenatal exposure to airborne PAHs was associated with decreased scores of nonverbal reasoning ability at 5 years of age. The reduction in nonverbal reasoning ability associated with high airborne PAH exposure corresponded to an estimated average decrease of 3.8 IQ points. The authors conclude that prenatal exposure to airborne PAHs adversely affects children’s cognitive development by 5 years of age. These findings have potential implications for school performance.

The Economist – Energy in the developing world

September 3, 2010 · 0 comments

Sept 2, 2010 – Energy in the developing world: Power to the people

Technology and development: A growing number of initiatives are promoting bottom-up ways to deliver energy to the world’s poor

AROUND 1.5 billion people, or more than a fifth of the world’s population, have no access to electricity, and a billion more have only an unreliable and intermittent supply. Of the people without electricity, 85% live in rural areas or on the fringes of cities. Extending energy grids into these areas is expensive: the United Nations estimates that an average of $35 billion-40 billion a year needs to be invested until 2030 so everyone on the planet can cook, heat and light their premises, and have energy for productive uses such as schooling. On current trends, however, the number of “energy poor” people will barely budge, and 16% of the world’s population will still have no electricity by 2030, according to the International Energy Agency.

But why wait for top-down solutions? Providing energy in a bottom-up way instead has a lot to recommend it. There is no need to wait for politicians or utilities to act. The technology in question, from solar panels to low-energy light-emitting diodes (LEDs), is rapidly falling in price. Local, bottom-up systems may be more sustainable and produce fewer carbon emissions than centralised schemes. In the rich world, in fact, the trend is towards a more flexible system of distributed, sustainable power sources. The developing world has an opportunity to leapfrog the centralised model, just as it leapfrogged fixed-line telecoms and went straight to mobile phones.

But just as the spread of mobile phones was helped along by new business models, such as pre-paid airtime cards and village “telephone ladies”, new approaches are now needed. “We need to reinvent how energy is delivered,” says Simon Desjardins, who manages a programme at the Shell Foundation that invests in for-profit ways to deliver energy to the poor. “Companies need to come up with innovative business models and technology.” Fortunately, lots of people are doing just that.

Read More – http://www.economist.com/node/16909923?story_id=16909923&fsrc=rss

Cornell University wins biochar/stove research grants

September 3, 2010 · 1 comment

Sept 2, 2010 – $3.3 million in grants aims to improve farming in Africa

Two Cornell-based research projects — one that boosts the soil-building effects of biochar for plants and another that harnesses genomics technology to accelerate maize and sorghum breeding in Africa by three-to-four times — have each been given more than $1.6 million in grants.

The research is funded by Basic Research to Enable Agricultural Development (BREAD), which is supported by the National Science Foundation (NSF) and the Bill and Melinda Gates Foundation. BREAD seeks to partner advanced research expertise with the developing world. NSF supports research components in the United States while the Gates foundation supports affiliated partners overseas.

The first project aims to develop microorganisms (inoculants) to add to biochars, produced when organic waste is burned at low temperatures without oxygen, to improve soil health in small farms in Kenya, where soil degradation is directly linked to food insecurity, hunger and poverty.

Lehmann’s group also seeks to develop stoves that would be made locally in Africa. The stoves would produce biochar while they were used for cooking and would eliminate indoor smoke, a serious health consequence of wood stoves in Africa. Also, farmers would be able to use such on-farm waste as shrubs, grasses and crop residues — rather than harder-to-find wood — to fire up the stoves.

The $1.6 million project also includes outreach to spread information and protocols about biochar, inoculants and cook stoves through workshops, presentations, CDs and publications.

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Updated IAP bibliographies of studies by Ezatti, Rehfeuss and Smith

August 30, 2010 · 1 comment

The Environmental Health Webliography contains citations and abstracts to some of the key environmental heath studies, by 22 authors, that were published from 2008 to the present.

Below are links to studies by 3 authors/researchers on IAP issues.

Please let me know if you have suggestions for other authors to add to the webliography

Eva Rehfuess – Selected studies, Mar 2006 – July 2010
http://ehbibliography.wordpress.com/category/rehfuess-e

  • Bayesian modelling of household solid fuel use: Insights towards designing effective interventions to promote fuel switching in Africa.
  • Risk of low birth weight and stillbirth associated with indoor air pollution from solid fuel use in developing countries.
  • Assessing household solid fuel use: multiple implications for the Millennium Development Goals

Kirk Smith: Selected Jan 2009 – Aug 2010 studies
http://ehbibliography.wordpress.com/category/smith-k

  • Mind the Gap.
  • Personal child and mother carbon monoxide exposures and kitchen levels: methods and results from a randomized trial of woodfired chimney cookstoves in Guatemala (RESPIRE).
  • Estimating personal PM2.5 exposures using CO measurements in Guatemalan households cooking with wood fuel.
  • Tuberculosis and indoor biomass and kerosene use in Nepal: a case-control study.
  • Oxidative injury in the lungs of neonatal rats following short-term exposure to ultrafine iron and soot particles.
  • Public health benefits of strategies to reduce greenhouse-gas emissions: overview and implications for policy makers.
  • Public health benefits of strategies to reduce greenhouse-gas emissions: health implications of short-lived greenhouse pollutants.
  • Public health benefits of strategies to reduce greenhouse-gas emissions: household energy.
  • Effect of reducing indoor air pollution on women’s respiratory symptoms and lung function: the RESPIRE Randomized Trial, Guatemala.
  • Personal child and mother carbon monoxide exposures and kitchen levels: Methods and results from a randomized trial of woodfired chimney cookstoves in Guatemala (RESPIRE).
  • Combining individual- and group-level exposure information: child carbon monoxide in the Guatemala woodstove randomized control trial.

Majid Ezzati – Selected studies, Sept 2008 – May 2010
http://ehbibliography.wordpress.com/category/ezzati-m

  • Within-neighborhood patterns and sources of particle pollution: mobile monitoring and geographic information system analysis in four communities in Accra, Ghana.
  • Association between tobacco smoking and active tuberculosis in Taiwan: prospective cohort study.
  • Comparative impact assessment of child pneumonia interventions.
  • Effects of smoking and solid-fuel use on COPD, lung cancer, and tuberculosis in China: a time-based, multiple risk factor, modelling study.
  • Characterizing air pollution in two low-income neighborhoods in Accra, Ghana.

Child mortality from solid-fuel use in India

August 26, 2010 · 0 comments

BMC Public Health 2010, 10:491doi:10.1186/1471-2458-10-491

Full-text: http://www.biomedcentral.com/1471-2458/10/491/abstract

Child mortality from solid-fuel use in India: a nationally-representative case-control study

Diego G Bassani , Prabhat Jha , Neeraj Dhingra and Rajesh Kumar

Published: 17 August 2010

Background – Most households in developing countries, including in India, use solid fuels (coal/coke/lignite, firewood, dung, and crop residue) for cooking and heating. Such fuels increase child mortality, chiefly from acute respiratory infection. There are, however, few direct estimates of the impact of solid fuel on child mortality in India.

Methods – We compared household solid fuel use in 1998 between 6790 child deaths, from all causes, in the previous year and 609601 living children from 1.1 million nationally-representative homes in India. Analysis were stratified by child’s gender, age (neonatal, post-neonatal, 1-4 years) and colder versus warmer states. We also examined the association of solid fuel to non-fatal pneumonias.

Results – Solid fuel use was very common (87% in households with child deaths and 77% in households with living children). After adjustment for demographic factors and living conditions, solid-fuel use significantly increase child deaths at ages 1-4 (prevalence ratio (PR) boys: 1.30, 95%CI 1.08-1.56; girls: 1.33, 95%CI 1.12-1.58). More girls than boys died from exposure to solid fuels. Solid fuel use was also associated with non-fatal pneumonia (boys: PR 1.54 95%CI 1.01-2.35; girls: PR 1.94 95%CI 1.13-3.33).

Conclusions – Child mortality risks from all causes due to solid fuel exposure were lower than previous estimates, but as exposure was common, solid fuel caused 6% of all deaths at ages 0-4, 20% of deaths at ages 1-4 or 128000 child deaths in India in 2004. Solid fuel use has declined only modestly in the last decade. Aside from reducing exposure, complementary strategies such as immunization and treatment could also reduce child mortality from acute respiratory infections.

Respiratory health effects of indoor air pollution

August 26, 2010 · 0 comments

INT J TUBERC LUNG DIS 14(9):1079–1086 2010

Respiratory health effects of indoor air pollution

Link: http://www.ingentaconnect.com/content/iuatld/ijtld/2010/00000014/00000009/art00003

R. Perez-Padilla,* A. Schilmann,† H. Riojas-Rodriguez†
* Instituto Nacional de Enfermedades Respiratorias, Mexico City, † Instituto Nacional de Salud Pública, Cuernavaca, Morelos, Mexico

Domestic pollution is relevant to health because people spend most of their time indoors. One half of the world’s population is exposed to high concentrations of solid fuel smoke (biomass and coal) that are produced by inefficient open fires, mainly in the rural areas of developing countries. Concentrations of particulate matter in kitchens increase to the range of milligrams per cubic meter during cooking. Solid fuel smoke possesses the majority of the toxins found in tobacco smoke and has also been associated with a variety of diseases, such as chronic obstructive pulmonary disease in women, acute respiratory infection in children and lung cancer in women (if exposed to coal smoke).

Other tobacco smoke-associated diseases, such as tuberculosis, asthma, respiratory tract cancer and interstitial lung diseases, may also be associated with solid fuel smoke inhalation, but evidence is limited. As the desirable change to clean fuels is unlikely, efforts have been made to use efficient, vented wood or coal stoves, with varied success due to inconsistent acceptance by the community.

Emission Factors of Particulate Matter in Stoves in China

August 26, 2010 · 0 comments

Environ Sci Technol. 2010 Aug 24.

Emission Factors of Particulate Matter and Elemental Carbon for Crop Residues and Coals Burned in Typical Household Stoves in China.

Full-text: http://pubs.acs.org/doi/full/10.1021/es101313y

Shen G, Yang Y, Wang W, Tao S, Zhu C, Min Y, Xue M, Ding J, Wang B, Wang R, Shen H, Li W, Wang X, Russell AG.

Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China, and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332.

Both particulate matter (PM) and black carbon (BC) impact climate change and human health. Uncertainties in emission inventories of PM and BC are partially due to large variation of measured emission factors (EFs) and lack of EFs from developing countries. Although there is a debate whether thermal-optically measured elemental carbon (EC) may be referred to as BC, EC is often treated as the same mass of BC.

In this study, EFs of PM (EF(PM)) and EC (EF(EC)) for 9 crop residues and 5 coals were measured in actual rural cooking and coal stoves using the carbon mass balance method. The dependence of the EFs on fuel properties and combustion conditions was investigated. It was found that the mean EF(PM) were 8.19 +/- 4.27 and 3.17 +/- 4.67 g/kg and the mean EF(EC) were 1.38 +/- 0.70 and 0.23 +/- 0.36 g/kg for crop residues and coals, respectively. PM with size less than 10 mum (PM(10)) from crop residues were dominated by particles of aerodynamic size ranging from 0.7 to 2.1 mum, while the most abundant size ranges of PM(10) from coals were either from 0.7 to 2.1 mum or less than 0.7 mum.

Of various fuel properties and combustion conditions tested, fuel moisture and modified combustion efficiency (MCE) were the most critical factors affecting EF(PM) and EF(EC) for crop residues. For coal combustion, EF(PM) were primarily affected by MCE and volatile matter, whereas EF(EC) were significantly influenced by ash content, volatile matter, heat value, and MCE. It was also found that EC emissions were significantly correlated with emissions of PM with size less than 0.4 mum.

Why the market alone cannot solve the clean cookstove gap

August 25, 2010 · 0 comments

Why the market alone cannot solve the clean cookstove gap

Could it be that the emphasis on finding market-based solutions to energy poverty alleviation and the large-scale deployment of improved cookstoves is just not practical?

“Probably,” say a group of researchers investigating the pressures placed on grass-roots NGOs to adopt market-based approaches to solving household energy and health issues in the developing world.

This is not to say that the market-based approaches cannot be effective under specific conditions, say the researchers, citing positive outcomes in China and Kenya.

Bailis et al 2009 Arresting the Killer in the Kitchen, whose research is based on a case study in Mexico, is an important read for all those trying to apply traditional market principles to the deployment of improved stoves.

In its conclusion, the authors affirm that, through their research, they have demonstrated that extended state and/or donor support has played a vital role in the success of past interventions and question the idea that it be reduced or removed.

Indeed, they add, we caution that the drive for commercialization carries risks for stove producers and their potential beneficiaries that appear to be downplayed by the proponents of commercialization.

J. Kim Chaix, CEO & Founder, Charcoal Project
http://www.charcoalproject.org

Testing biomass cookstoves in rural Kenyan schools

August 25, 2010 · 0 comments

Energy for Sustainable Development, July 2010

Testing institutional biomass cookstoves in rural Kenyan schools for the Millennium Villages Project

Download Full-text (pdf, 649KB)

Edwin Adkins, et al.

Cooking tests were conducted in randomly selected school kitchens in the Sauri Millennium Villages Project site, located in Siaya District of Nyanza Province in Western Kenya. The tests compared fuel consumption measurements obtained using a traditional three-stone fire with those from newly introduced institutional stoves based on the “rocket” design. The key metric used was Specific Fuel Consumption (SFC), defined as the weight of firewood consumed in cooking a single batch of food divided by the total weight of food, measured after cooking.

Tests followed the normal cooking practices in the school kitchens and included the typical range of foods prepared for midday school meals programs. The study included two types of tests: paired tests, in which most conditions were controlled between one test conducted on a three-stone fire and a matching test conducted on a “rocket” stove; and unpaired tests, in which conditions were similar, but not strictly controlled, among two large sets of relatively independent three-stone fire and rocket stove tests.

Results from both paired and unpaired experiments, averaged across all types of food cooked, showed that the use of rocket stoves yielded significantly lower SFC values without prolonging cooking time when compared with three-stone fires. An analysis comparing results from paired and unpaired cooking tests suggests that, due to high variance and sources of bias in unpaired tests, experimental design should favor paired tests.

Kirk Smith study – Mind the Gap

August 24, 2010 · 0 comments

Environ Health Perspect. 2010 Aug 20.

Mind the Gap

Download Full-text

Smith KR, Peel JL. University of California.

Background: Recent analysis has demonstrated a remarkably consistent, non-linear relationship between estimated inhaled dose of combustion particles measured as PM2.5 and cardiovascular disease mortality over several orders of magnitude of dose – from cigarette smoking, secondhand tobacco smoke exposure, and ambient air pollution exposure.

Objectives: Here we discuss the implications of this relationship and point out gaps in our knowledge that it reveals.

Discussions: The non-linear exposure-response relationship that is revealed – much steeper at lower than at higher doses – explains the seemingly inconsistent risks observed from ambient air pollution and cigarette smoking but also raises important questions about the relative benefits of control at different points along the curve. This analysis also reveals a gap in the evidence base along the dose-response curve between secondhand tobacco smoke and active smoking, which is the dose range experienced by half the world’s population from indoor biomass and coal burning for cooking and heating.

Conclusions: The shape of the exposure-response relationship implies much larger public health benefits of reductions at the lower end of the dose spectrum, for example from reductions in outdoor air pollution than from reducing the rate of active smoking, which seems counter-intuitive and deserving of further study because of its importance for control policies. In addition, given the potential risks and consequent global disease burden, epidemiological studies are urgently needed to quantify the cardiovascular risks of particulate matter exposures from indoor biomass burning in developing countries, which lie in the dose gap of current evidence.

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