Split wood, not atoms.
From the start of the genetic modification of a certain subset of hominid great apes about a few hundred thousand years ago - another word for "genetic modification" is evolution - to create the modern species called Homo sapiens (although one may sometimes doubt if the name "sapiens" is actually appropriate), so called "renewable energy" has dominated human technological applications. It still does.
The list of countries where so called "renewable energy" dominates are generally included in another list, the list of "poor countries."
The paper from the primary scientific literature that I will discuss in this brief diary is from a journal I often cite (because I scan and read portions of every issue), Environmental Science and Technology, a publication of the American Chemical Society, one of the world's largest and oldest scientific organizations.
The paper is written by researchers at Harvard School of Public Health, a Gambian scientist and some Europeans thrown in just for fun.
The reference is Environ. Sci. Technol. 2012, 46, 3519−3527
The title of the paper is "Household Concentrations and Exposure of Children to
Particulate Matter from Biomass Fuels in The Gambia."
The Gambia is 154th of the Wikipedia list of life expectancy in countries around the World. According to the US State Department the per capita income of the Gambia is $517 per year, which is smaller than the tax break you can get in the nearly bankrupt State of California to install a solar PV system to power one of those swell swell (highly subsidized) electric Tesla cars that everyone's driving and everyone can buy for "only" about $100,000.
The region of The Gambia, is, by the way, was the home of the ancestors of many modern Americans, ancestors who were forcibly and criminally abducted by other ancestors of modern North Americans and deprived of ownership even of their own flesh for generations.
Just saying...
Here's the introduction to the paper:
Biomass fuels and coal are the primary source of energy for cooking and heating for approximately one-half of the world’s population, and 80% of the population of sub-Saharan Africa.1 In most developing countries, biomass is burned in traditional open fires leading to high concentrations of multiple pollutants. 1−3 Women and young children may spend hours near cooking fires, and hence have high exposures. There is increasing evidence that biomass smoke is a risk factor for pneumonia, the leading cause of child death worldwide.4 Air pollution is a complex mixture of solid and gaseous pollutants. Although multiple components of combustion air pollution are associated with adverse health outcomes, particulate matter (PM) has been consistently, independently, and coherently related to various diseases affected by air pollution. 5−8 Measuring personal exposure of children to PM is difficult because current PM monitors are too large and heavy to be carried by a small child for many hours.
What the authors do to overcome the burden of children carrying around PM monitors in The Gambia is to validate a method whereby exposure to carbon monoxide, the well known hematological poison (and useful chemical synthesis intermediate) is correlated to PM exposure.
Here's what the authors say about that:
We estimated the relationship between cookhouse integrated PM2.5 and CO using the 197 colocated measurements. To assess whether variables available in questionnaires help improve PM2.5 prediction, we developed a series of regression models with different covariates including fuel used for cooking, cooking location and duration, study site, and measurement season. We also considered the interactions among variables. We applied natural splines with 2−6 degrees of freedom because exploratory analysis showed that the PM2.5−CO relationship was nonlinear (Figures 1 and 2). We developed a total of 36 regression models. We used the Akaike information criterion (AIC) and Bayesian information criterion (BIC) to evaluate the models.
Here's some heartrending descriptions of the validation study:
Direct PM2.5 Exposure (Validation Study). We directly measured personal exposure to PM2.5 on 48 children between January 2010 and January 2011 (Table S1). These children were aged between 15 and 61 months at the time of measurement, with a mean and median age of 34 months, and standard deviation of 9 months. There were no other criteria for their selection beyond being eligible for measurement at the time of the study and being large enough to comfortably carry the backpack containing measurement equipment. Each child wore a toddler-sized backpack (Figure 3) fitted with a PM2.5 monitor for 48-h. We could not measure personal exposure on younger children because they were too small to carry the backpack and monitor. Five children were excluded from analysis because of initial equipment failure or because the backpack was removed due to child’s illness or inability to carry the backpack; 12 were excluded because the monitor operated for less than 38.4-h (80% of the target 48-h period). The remaining 31 children were included in analysis. Of these, 29 had valid simultaneously measured personal CO exposure; CO exposure measurements were initiated 24-h prior to the start of PM exposure measurement, to ensure that there was sufficient color change on the CO tubes.
Here's what the authors found in cookhouses in The Gambia:
Cookhouse PM2.5and CO. Mean 72-h cookhouse PM2.5 concentration in the 203 households with 219 measurements was 395 ± 364 μg/m3. This is substantially higher than PM2.5 cookhouse concentrations in China of 107 μg/m3 18 but lower than the 900 μg/m3 in kitchens with open fires in Guatemala.13 With somewhat different size fractions, mean PM4 concentrations were 500 μg/m3 in kitchens of wood users in India,26 and ranged from 187 to 719 μg/m3 in different provinces and seasons in China.27 Mean 72-h cookhouse CO concentration was 6.7 ± 7.3 ppm (356 measurements in 322 households), lower than the 10−11 ppm in Guatemala before stove interventions, 28 and similar to those in the nonheating season in China (5.5 ppm).27 Both the China and Guatemala studies used a different brand of CO diffusion tube than was used in our study in The Gambia.
Things could be worse. You could live in Guatemala.
The study involves direct measurement of the exposure of 1266 children in The Gambia.
Study Area, Population, and Participants. Our study took place in The Gambia, in the greater Banjul area and the Basse area of the Upper River Region. The study areas consist primarily of periurban and rural locations, but a few urban homes were also included. Study participants were children aged between 2 and 59 months at the time of recruitment into an epidemiologic study of child pneumonia conducted at the Medical Research Council (MRC), The Gambia Unit. Details on the study area and population, recruitment, and the child-care behaviors, cooking fuel and location, and demographic characteristics of study participants are provided elsewhere. 12 At the time of this analysis, 1303 children had been enrolled. Of these, 37 withdrew from the study as detailed elsewhere,12 and were excluded from all analyses, leaving a sample of 1266 children.
By the way here is the web page of The Gambia's Ministry of Energy:
The Gambia Ministry of Energy. You may click on the link therein to learn about the official energy policy of that country, a big part of which is "get more wood."
Split wood, not atoms.
Well, as always, it's been a pleasure chatting with you.
Have a nice day.