Health Risks

Researchers at Harvard University’s Science, Technology and Public Policy Program define energy technology innovation (ETI) as the set of processes leading to new or improved energy technologies that can augment energy resources and reduce the economic, environmental or political costs associated with energy supply and use. These researchers note that traditional biomass remains the dominant contributor to the energy supply of developing countries, serving household energy needs of a significant proportion of humanity, in cook stoves or open fires. Among their conclusions is that there is still much to be done in ETI in shifting to cleaner cook stoves in order to reduce the enormous human health, socioeconomic and environmental impact of current biomass use.

The patent-pending improved combustion stove we present here is an energy technology innovation (ETI) that has the potential for a substantive positive impact upon the health and well-being of millions of individuals in developing countries worldwide. We believe that this stove meets criteria suggested by the Appropriate Infrastructure Development Group (AIDG) that innovation that makes life easier for the world’s poor needs to be affordable, repairable, reliable and environmentally sound.

Indoor air pollution (IAP) in developing countries is a major environmental and public health challenge according to numerous publications by World Health Organization (WHO) scientists. Wood, animal dung, crop residues and coal are used extensively for domestic (cooking and heating) needs. Combustion produces many toxic pollutants including small particulate matter, carbon monoxide, nitrous oxide, sulfur oxides, formaldehyde, carcinogenic polycyclic organic matter and elemental residues. The WHO reports note that 50% of the world population relies on such materials and these are typically burnt in simple stoves with very incomplete combustion. Especially in homes where coal is used for domestic heating and cooking, there is a potential serious human health problem because the coal generally is mined locally with little regard to its composition. It is burned, usually incompletely, in poorly vented or unvented stoves, directly exposing residents to the emissions.

In particular, women and young children are at risk because of their household roles. There is increased incidence of chronic obstructive lung disease and acute respiratory infections in childhood, the most important cause of death among children under 5 years old in developing countries. There is also association with low birth weight, increased infant and perinatal mortality, pulmonary tuberculosis, nasopharyngeal and laryngeal cancer, cataract formation, and with coal use, lung cancer.

Researchers at the Science, Technology and Environmental Policy Program at Princeton University, in collaboration with WHO scientists, write that exposure to IAP from the combustion of bio-fuels, especially particulate matter, has been implicated as a causal agent of respiratory diseases in developing countries. That globally more than 2 billion people rely on biomass fuel as the primary source of domestic energy has put preventative measures to reduce exposure to IAP high on the agenda of international development and public health organizations. Specifically, they mention the design and dissemination of improved stoves and fuels as measures that aim to reduce these negative health impacts.

As has been reported elsewhere in this offering, it has been estimated that a substantial portion of China’s coal is used for domestic (home) energy needs. About 400 million people in China are thought to rely on coal for this purpose. The unprocessed coal is commonly burned in unvented stoves that permeate their homes with high levels of toxic metal and organic compounds, in addition to previously mentioned pollutants. Based upon research from the US Geologic Survey and the Institute of Geochemistry at Guiyang in Guizhou Province, severe arsenic poisoning, dental and skeletal fluorosis, selenium and possibly mercury poisoning result from the domestic combustion of metal-laden coals. Furthermore, coal combustion produces polycyclic aromatic hydrocarbons thought to cause or contribute to the high incidence of esophageal and lung cancers in parts of China.

The populace of China is not alone in IAP exposure. Published research documents the same risks to millions of people in sub-Sahara Africa and India. Publication of peer-reviewed research from the University of California Berkeley School of Public Health corroborates that in India, like other developing countries, there is widespread practice of using unprocessed solid fuels (coal and biomass) for cooking and/or space heating. Cooking is done in virtually every household every day in most of the world. With its large, poor, urban and rural populations still using simple solid fuels, these researchers note that the Indian population bears a significant fraction of world exposure to indoor combustion products of unprocessed solid fuels. Solid fuel stoves are well known to the Indian continent and would not require introduction, for it is estimated that India may already have approximately 30% of the global household stove distribution.

Stove smokeSophisticated epidemiological analysis suggests that air pollution in India would contribute between 6 to 9% of the total national burden of disease, nearly rivaling water, sanitation and hygiene. Therefore, in India, health effects of indoor air pollution rivals or exceeds tuberculosis, ischemic heart disease, all cancers, road accidents or all of the “tropical” diseases combined. Conservative estimates indicate 400-550 thousand premature deaths can be attributed annually to use of biomass fuels in these population groups. Acute respiratory infections, chronic obstructive pulmonary disease, lung cancer, asthma, tuberculosis and cataract-causing blindness have all been associated with exposure to biomass fuel-induced IAP in India, similar to the rest of the developing world.

The incomplete combustion of contaminates in wood, coal, and other fuel sources that are used in typical indoor stoves is the cause of toxicity and health problems. Enviro Fuels Manufacturing, Inc. has designed a stove and briquette-formulation that, when used in combination, go a long way toward solving the problem of incomplete combustion. Our Enviro HE Stove™ has the ability to produce nearly 100% combustion when used with Enviro Fuels CBF Pellets™, and remains safe to the touch on its exterior when the core temperature reaches 1400°F. The Enviro HE Stove™ design directs the heat generated in its heat chamber to the burner level, preventing the heat dissipation that occurs with other stoves. This fact, coupled with superior combustion efficiency, results in less fuel necessary for cooking. Tests have shown that the Enviro HE Stove™ requires no more than one third of the fuel required in current commonly used stoves to achieve the same useable heat for the same amount of time. The result is far less cost to the user with virtually emission-free combustion.