After writing my most recent blog on the installation of solar panels on a Navajo hogan, I received email from a man who has lived on the Navajo reservation for 30 years: "I think your perspectives on Navajo today were quite precise, causing me to wonder who you might be. I'm enjoying your work." So maybe I'm not crazy!

My correspondent took exception to an assertion by Mark Snyder that the coal-fired generating plants on the reservation are to blame for the high rates of asthma, chronic bronchitis, lung cancer, and heart disease among the Navajo: "There are no scientific studies to substantiate this statement and I've been looking online since last September and have checked with the Navajo Area Indian Health Service whether they are aware of any. They're not."

He attached an article, "Navajo Coal Combustion and Respiratory Health Near Shiprock, New Mexico," published in a peer-reviewed journal, the Journal of Environmental and Public Health. Some extracts follow.

Indoor air pollution has been identified as a major risk factor for acute and chronic respiratory diseases throughout the world ... In twenty-five percent of homes surveyed [on the Navajo Nation reservation] coal was burned in stoves not designed for that fuel, and indoor air quality was frequently found to be of a level to raise concerns ...

The majority of those surveyed used an indoor stove for heating (105 of 137, 77%); the remainder had electrical or other heating units. One quarter (34 of 137, 25%) of those surveyed were burning coal in stoves that were not designed to operate at the higher temperatures at which coal burns as compared to wood, and many of the stoves had visible cracks or were poorly ventilated to the outside ... Most stoves had chimneys (106 of 117, 91%); however many chimneys had holes, cracks, and п¬Ѓssures ...

We found that the respiratory disease burden (as measured by hospital admissions and outpatient visits to the NNMC for the seven disease/conditions noted) is increased in the winter as compared to summer (Figure 1), and yet the power plant emissions are greater in the summer than those in the winter ...

This report presents the п¬Ѓrst systematic study of coal combustion's likely impacts on respiratory health in Shiprock area of the Navajo Nation. Over 130 homes in the Shiprock area were surveyed, and stoves in one-quarter of those homes were found to be inappropriate for coal combustion, even typical for most of the Reservation. The presence of two large coal-п¬Ѓred power plants near Shiprock may contribute to that risk, but results from this study suggest that the risk could be reduced by making relatively simple and inexpensive changes to methods of home heating.

So it looks like Elsa Johnson, Mark Snyder and others who wish to make a difference among the Navajo could have a larger impact by fixing the inadequate stoves there. It costs $60,000 to bring solar electricity to one hogan. How many homes could be fitted with new coal-burning stoves for that amount of money? I'm guessing more than one.

Henry Percy is the nom de guerre for a technical writer living in Arizona. He may be reached at saler.50d[at]gmail.com.