The Netherlands solid fuels circulation system

Nearly 3 billion people worldwide, and a great majority of households in developing countries, rely on solid fuels (such as wood, dung, crop residues, coal, and charcoal) with little or no access to modern fuels for cooking and other household energy needs (Lim et al. 2012; Smith et al. 2012). In these households, solid fuels are often burned in inefficient, poorly vented combustion devices (open fires, traditional stoves). The incomplete combustion of these solid fuels results in much of the fuel energy being emitted as potentially toxic pollutants, including particles of varying sizes, carbon monoxide (CO), nitrogen dioxide, volatile and semivolatile organic compounds (e.g., formaldehyde and benzo[a]pyrene), methylene chloride, and dioxins (Naeher et al. 2007). Combustion of coal, in addition to the above pollutants, releases sulfur oxides, heavy metals such as arsenic, and fluorine [World Health Organization (WHO) 2006]. The use of solid fuels, primarily for cooking, has been estimated to be responsible for > 3.5 million premature deaths per year (plus an additional 0.5 million deaths from outdoor air pollution due to household fuel use) and 110 million disability-adjusted life years (DALYs) (Lim et al. 2012).

Having a solid fuels circulation system is clearly an advantage in terms of building computer simulation programs that will effectively predict equipment performance; offers methods to formulate sound mathematical models for boilers, gasifiers, furnaces, and incinerators’ interpret simulation results for the best design and operation of combustion and gasification equipment; describes key aspects of solid and gas combustion phenomena, enables discussions of the basic and auxiliary equations used in specific projection models; and includes applications of moving and fluidized beds.

Source: World Health Organization, 2015

Solid fuels combustion and gasification: modeling, simulation, and equipment operation 

Regionally, the European Union has established policies to support the circulation system of solid fuels. The Netherlands has a robust circulation system in The Netherlands. It has demonstrated an operation mechanism, modeling, and simulation of equipment for the combustion and gasification of solid fuels. The country has clearly illustrated procedures to improve and optimize the design of future units and the operation of existing industrial systems with recommendations and guidelines from a seasoned professional in the field.

The country has several large-scale initiatives that are under way for the dissemination of cleaner-burning stoves (Martin et al. 2011); however, the stoves being disseminated may not achieve the desired exposure reductions and health benefits given the lack of robust exposure？ response information. These high-profile efforts are building needed momentum and bringing financial support and attention to this important global health issue. For example, the Global Alliance for Clean Cookstoves (GACC) is a public-private partnership led by the United Nations Foundation whose goal is for 100 million homes worldwide to adopt clean, efficient stoves and fuels by 2020 (GACC 2012). In the face of immense practical and cultural barriers to sustainable and effective cookstove interventions, for this effort and others like it to be successful in the design and dissemination of cleaner-burning cookstoves that will meaningfully improve health, the fundamental question “How clean is clean enough?” must be answered. Despite this knowledge gap, an international work- shop consisting of 91 stakeholders (cookstove manufacturers, disseminators, researchers, and academics) from 23 countries developed a guidance policy on emissions testing and voluntary standards for improved cookstoves (International Standards Organization 2012). Although the policy relies on a set of tiers for exposure reduction rather than specify- ing a health-based emissions standard, it does note the need to incorporate the results of future studies to specify such a health- based standard.

Gaps and ways of working in establishing policies to support solid fuels circulation system

The extreme variability within and between personal exposures to cookstove-related air pollution, as well as multiple sources of exposure measurement error, are major sources of uncertainty around the exposure？response curve. For example, Smith et al. (2011) reported the first exposure？response evaluation within a cookstove intervention study; the results illustrated the difficulty in estimating health outcome improvements from specific intervention-related exposure reductions. A 50% reduction in personal CO exposure comparing group means for the control and intervention arms of the trial was associated with an estimated 18% reduction in risk for physician-diagnosed pneumonia in children; however, the 95% confidence interval (CI) suggests that these data are consistent with a risk reduction that ranges from 2% to 30% (Smith et al. 2011).

In May 2011, an international workshop, “Health Burden of Indoor Air Pollution on Women and Children in Developing Countries,” led by the National Institutes of Health, convened > 150 participants to review the state of the science regarding the health impacts of exposures to air pollution from the household use of solid fuels including indoor, near household, and outdoor environments [household air pollution (HAP)]. Acknowledging the consider- able progress achieved to date by previous research, the workshop’s Exposure Assessment and Biomarkers Working Group identified several research priorities as potentially having the biggest impact on the cookstove field, focusing specifically on information needed to better inform stove dissemination programs. The working group discussed questions regarding critical site-specific design choices, such as the duration of the measurement (e.g., cooking period, 24 hr, 48 hr), the num- ber of repeated measures necessary to characterize temporal variability, and the monitor type (area vs. personal) and placement necessary to characterize spatial variability; the relevant pollutants of interest; as well as the appropriate methods to estimate pollutant dose. Here, we summarize the existing state of the knowledge, identify gaps, and provide recommendations for exposure assessment research needed to answer the question “How clean is clean enough?”

WHO’s solution in the European Union region

The World Health Organization’s latest guidelines for indoor air quality on household-fuel combustion set for the first time emission targets to address the serious health risks from burning sold fuels. They also oppose the use of unprocessed coal and kerosene, which severely pollutes indoor air and creates risks of fire, burns and poisoning. Worldwide, nearly 3 billion people still lack access to clean fuels and technology for cooking. In 2012, according to a WHO report, 4.3 million people died prematurely as a result of household air pollution.

While cooking over an open fire is not commonplace in countries in the WHO European Region, the health-and climate-damaging effects from burning solid fuels, including wood and other biomass, for domestic heating remain critical issues. Over 117 000 deaths due to household air pollution occurred in the Region in 2012. Household-fuel combustion also contributes to outdoor air pollution, which was responsible for over 482 000 deaths in the European Region in 2012. Where use of solid fuel is widespread across a community, emissions may result in outdoor air pollution exceeding values in the WHO air quality guidelines. Deaths from outdoor air pollution occur in all European countries, regardless of income, but those from household air pollution are over five times greater in low- and middle-income countries than in wealthier ones.

Meeting new emission targets means that some 90% of homes globally will meet WHO’s air quality guideline values. The guidelines’ recommendations stress the need to improve access to cleaner home energy sources, particularly in low- and middle-income countries. Clean, sustainable sources of household fuel have an important role in climate change mitigation especially by reducing substantial carbon dioxide (CO2) emissions. WHO recommends that governments and other agencies developing and implementing policy on mitigating climate change consider action on household energy, and make assessments to maximize health and climate gains. In addition, clean technologies and fuels must be affordable by the lowest-income households.

In the 2010 Parma Declaration on Environment and Health, Member States in the Region committed themselves to preventing disease by improving outdoor and indoor air quality. WHO will support European countries in implementing the new guidelines, which will be reviewed and updated periodically. The Task Force on the Health Aspects of Long-range Transboundary Air Pollution, chaired by WHO/Europe’s European Centre for Environment and Health, will use the most recent results to intensify support to Member States that develop their policies independently from European Union (EU) processes. WHO/Europe works on climate change and health by addressing the health benefits of policies reducing greenhouse gas emissions in a variety of sectors.

Conclusion

Across Europe, central Europe is the region with the highest proportion of outdoor particulate matter with an aerodynamic diameter of less than 2.5 micrometres (PM2.5) that can be traced to residential heating with solid fuels (21% in 2010). Evidence links emissions from wood and coal heating to serious health effects such as respiratory and cardiovascular mortality and morbidity. Wood and coal burning also emit carcinogenic compounds. Each year 61 000 premature deaths are attributable to ambient air pollution from residential heating with wood and coal in Europe, with an additional 10 000 attributable deaths in North America (Ibid, 22).

Measures are available to reduce emissions of solid fuels for residential heating in most places. Encouraging fuel switching (away from coal and other solid fuels) and use of more efficient heating technologies (such as certified fireplaces or pellet stoves) can reduce the emissions from residential wood and coal heating devices.

Existing regulatory measures include ecodesign regulations and labels in the European Union (EU) and technology- based emission limits in the United States of America and Canada. Financial fuel switching and technology change- out incentives ？ as well as targeted “no burn” days and ecolabelling ？ are other tools available to policy-makers.

Given the substantial contributions to air pollution from residential heating with solid fuels, it will be difficult to tackle outdoor air pollution problems in many parts of the world without addressing this source sector. Nevertheless, the use of solid fuels for heating is expected to persist and probably even expand, especially within the EU, in the coming decades as a result of climate policies that favour wood burning. Better alignment is therefore needed between climate and air pollution policies in many countries. Information campaigns ？ especially those that increase knowledge about the energy efficiency of heating options ？ are encouraged. Educational campaigns may also be useful tools to reduce emissions from residential solid fuel heaters. Furthermore, filters may reduce health effects from indoor air pollution.

As new wood-burning devices become more energy efficient and emit less pollution (especially PM), national governments need to prepare heater exchange regulations or voluntary programmes. Municipalities, counties and states should consider requiring heater exchanges at the time of home remodels or sales. In many cases, these regulations will be most successful if financial compensation is offered to assist with the cost of replacing old heaters with those meeting tight energy efficiency or emission limits regulations.

Local and regional authorities, with patient organizations, need to create community- wide information campaigns to inform residents about the climate and health benefits of local emission-free alternatives for house heating. These may include district heating by controlled combined heat and power plants, geothermal energy for single houses or as a larger local installation and heat pumps for single houses or apartments. Authorities could arrange distribution of leaflets and personal information to residents on how to arrange proper drying and storage of wood logs and how to use current small- scale heaters properly during annual chimney sweeps. An example of this is the information campaign implemented by chimney sweeps in Finland (Levander & Bodin, 2014). The most challenging task is to change the attitudes of people who are attached to the tradition of burning wood for house heating and comfort, and who often get their wood cheaply or without charge from their own or relatives’ and friends’ forests by harvesting small trees and making the wood logs in their spare time.

References:

Levander T, Bodin S (2014). Controlling emissions from wood burning: legislation and regulations in Nordic countries to control emissions from residential wood burning ？ an examination of past experience. Copenhagen: Nordic Council of Ministers.

Lim SS, Vos T, Flaxman AD, Danaei G, Shibuya K, Adair-Rohani H et al. (2012). A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990？2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet. 380:2224？2260.

Martin EA, Karr CJ, Koehoorn M, Demers PA, Tamburic L, Lencar C et al. (2011). Residential air pollution and otitis media during the first two years of life. Epidemiology. 22:81？89.

Naeher LP, Brauer M, Lipsett M, Zelikoff JT, Simpson CD, Koenig JQ et al. (2007). Woodsmoke health effects: a review. Inhal Toxicol. 19(1):67？106.

Smith K, Bruce N, Balakrishnan K, Adair-Rohani H, Balmes J, Chafe Z et al. (2012). Millions dead: how do we know and what does it mean? Methods used in the comparative risk assessment of household air pollution. Annu Rev Public Health. 35:185？206.

Smith K, McCracken JP, Weber M, Hubbard A, Jenny A, Thompson LM et al. (2011). Effect of reduction in household air pollution on childhood pneumonia in Guatemala (RESPIRE): a randomized controlled trial. Lancet. 378:1717？1726.