1 Programa de Bioestadística, Escuela de Salud Pública, Facultad de Medicina, Universidad de Chile, Santiago, CP 838046, Chile

2 Emory University Rollins School of Public Health, Atlanta, GA 30322, USA

3 International Exchange Program for Minority Student, Icahn School of Medicine at Mount Sinai in New York City, NY 10029, USA

4 Departamento de Salud Ambiental, Escuela Graduada de Salud Pública, Universidad de Puerto Rico recinto de Ciencias Médicas, San Juan, CP 00921, Puerto Rico

5 Centro de Estudio de Salud del Trabajador y Ecología Humana, Escuela Nacional de Salud Pública, Fio Cruz. Rio de Janeiro, CEP 21040-900, Brasil

6 Programa de Salud Ambiental, Escuela de Salud Pública, Facultad de Medicina, Universidad de Chile, Santiago, CP 838046, Chile


BACKGROUND AND OBJECTIVES: The goal of this study is to evaluate in a time-series study the short-term effects of particulate matter-2.5exposure on respiratory emergency visits in six central-southern Chilean cities highly contaminated by wood smoke.
METHODS: Association was assessed using both distributed lag linear and non-linear Poisson models constrained to a 7-day lag period, adjusting for temporal trends and meteorological variables and stratifying seasonally into cold and warm periods.
FINDING: The results showed that the daily average concentrations of particulate matter-2.5in the cold period were 3 to 6 times those recorded in the warm period, exceeding the daily norm of 50 µg/m3 the 93.3% of the time versus 6.7%, respectively. The average daily number of respiratory emergency visits were between 30% and 64% higher in the cold period compared to the warm one. From linear models, cumulative relative risk ratios over 0-7 day lags per 10 mg/m3 of fine particle increase were between 1.004 (95% confidence Interval: 0.998 - 1.010) and 1.061 (95% confidence Interval: 1.049 - 1.074); these annual effects are attributable to the cold period impact where the cumulative risk ratios  were between 1.008 (95% confidence Interval: 1.004 - 1.012) and 1.036 (95% confidence Interval: 1.026 - 1.047), since significant effects of fine particles on the studied risk were not found for the warm period.
CONCLUSION: With non-linear models we observed strong increasing associations with the level of particles for the overall period. High levels of fineparticles from firewood are associated with respiratory effects observable several days after exposure. Health effects found in this study suggest that current policies tending to mitigate woodsmoke-related emissions should continue and reinforce. 
©2021 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.

Graphical Abstract

The effect of short-term of fine particles on daily respiratory emergency in cities contaminated with wood smoke


  • Firewood combustion is the main source of PM2.5 in urban areas of central-southern in Chilean cities;
  • The daily average concentrations of PM2.5 exceeded significantly the daily norm of 50 µg/m3 on 93.3% of the days monitored in the cold period;
  • Daily respiratory emergency visits were 30% to 60% higher in the cold period compared to warm.
  • Short-term lag-effects of exposure to PM2.5 were significantly associated with daily respiratory emergency visits during cold period.


Main Subjects

Almon, S., (1965). The distributed lag between capital appropriations and expenditures. Econometrica: J. Econ. Soc., 178-196 (19 pages).

Armstrong, B., (2006). Models for the relationship between ambient temperature and daily mortality. Epidemiology. 17(6): 624-631  (8 pages).

Astudillo, P.; Prieto, C.; Mancilla, P., (2007). Exceso de morbilidad respiratoria en niños y adultos mayores en una comuna de Santiago con alta contaminación atmosférica por partículas. Rev. Méd. Chile. 135: 221-228 (8 pages).

Bede-Ojimadu, O.; Orisakwe, O.E., (2020). Exposure to Wood Smoke and Associated Health Effects in Sub-Saharan Africa: A Systematic Review. Ann. Global Health. 86: 32 (1 page).

Bergamaschi, E.; De Palma, G.; Mozzoni, P.; Vanni, S.; Vettori, M.V.; Broeckaert, F.; Bernard, A.; Mutti, A., (2001). Polymorphism of quinone-metabolizing enzymes and susceptibility to ozone-induced acute effects. Am. J. Respir. Crit. Care Med., 163(6): 1426-1431 (6 pages).

Cerda, A.A.; Garcia, L.Y., (2010). Hypothetical health and economic benefits associated with a reduction in air pollution in a Chilean city (Talca). Rev. Med. Chile. 138(11): 1395-1402 (8 pages).

Cifuentes, L.; Krupnick, A.; O´Ryan, R.; Toman, M., (2005). Urban Air quality and Human Health in Latin America and the Caribbean (85 pages).

Cifuentes, L.A.; Vega, J.; Kopfer, K.; Lave, L.B., (2000). Effect of the fine fraction of particulate matter versus the coarse mass and other pollutants on daily mortality in Santiago, Chile. J. Air Waste Manage. Assoc., 50(8): 1287-1298 (12 pages).

DEIS, (2019) Department of Statistics and Health Information (DEIS for its acronym in Spanish). Ministry of Health. Government of Chile.

Diociaiuti, M.; Balduzzi, M.; De Berardis, B.; Cattani, G.; Stacchini, G.; Ziemacki, G.; Marconi, A.; Paoletti, L., (2001). The two PM(2.5) (fine) and PM(2.5-10) (coarse) fractions: evidence of different biological activity. Environ. Res., 86(3): 254-262 (9 pages).

Dominici, F.; Samet, J.M.; Zeger, S.L., (2000). Combining evidence on air pollution and daily mortality from the 20 largest US cities: a hierarchical modelling strategy. Journal of the Royal Statistical Society: Series A., 163(3): 263-302 (40 pages).

Dominici, F.; Zanobetti, A.; Zeger, S.L.; Schwartz, J.; Samet, J.M., (2004). Hierarchical bivariate time series models: a combined analysis of the effects of particulate matter on morbidity and mortality. Biostatistics. 5(3): 341-360 (20 pages).

Fairley, D., (1999). Daily mortality and air pollution in Santa Clara County, California: 1989-1996. Environ. Health Perspect., 107(8): 637-641 (5 pages).

Gasparrini, A.; Armstrong, B.; Kenward, M.G., (2010). Distributed lag non-linear models. Stat. Med., 29(21): 2224-2234 (11 pages).

GEA, (2012) Global Energy Assessment: Toward a sustainable future (113 pages).

Geiger. R., (1954). Klassifikation der Klimate nach W. Köppen [Classification of climates after W. Köppen]. Landolt-Börnstein – Zahlenwerte und Funktionen aus Physik, Chemie, Astronomie, Geophysik und Technik, alte Serie. Berlin. 3: 603–607 (5 pages).

Ghio, A.J.; Cohen, M.D., (2005). Disruption of iron homeostasis as a mechanism of biologic effect by ambient air pollution particles. Inhal. Toxicol., 17(13): 709-716 (8 pages).

Goldberg, M.S.; Gasparrini, A.; Armstrong, B.; Valois, M.F., (2011). The short-term influence of temperature on daily mortality in the temperate climate of Montreal, Canada. Environ. Res., 111(6): 853-860 (8 pages).

Green, J.; Sánchez, S. (2013) Air Quality in Latin America: An overview. Washington D.C.-Updated version May 2013 (36 pages).

Guarnieri, M.; Balmes, J.R., (2014). Outdoor air pollution and asthma. Lancet, 383(9928): 1581-1592 (12 pages).

FAO, (2010) Food and Agriculture Organization of the United Nations (FAO). Criteria and indicators for sustainable wood fuels. Rome: FAO Forestry paper 160, (103 pages).

Hong, Y.C.; Pan, X.C.; Kim, S.Y.; Park, K.; Park, E.J.; Jin, X.; Yi, S.M.; Kim, Y.H.; Park, C.H.; Song, S.; Kim, H., (2010). Asian Dust Storm and pulmonary function of school children in Seoul. Sci. Total. Environ., 408(4): 754-759 (6 pages).

Ilabaca, M.; Olaeta, I.; Campos, E.; Villaire, J.; Tellez-Rojo, M.M.; Romieu, I., (1999). Association between levels of fine particulate and emergency visits for pneumonia and other respiratory illnesses among children in Santiago, Chile. J. Air Waste Manage. Assoc., 49(9 Spec No): 154-163 (10 pages).

Jorquera, H.; Barraza, F.; Heyer, J.; Valdivia, G.; Schiappacasse, L.N.; Montoya, L.D., (2018). Indoor PM2.5 in an urban zone with heavy wood smoke pollution: The case of Temuco, Chile. Environ. Pollut., 236: 477-487 (11 pages).

Koenig, J.Q,; Larson, T.V.; Hanley, Q.S.; Rebolledo, V.; Dumler, K.; Checkoway, H.; Wang, S.Z.; Lin, D.; Pierson, W.E., (1993). Pulmonary Function Changes in Children Associated With Fine Particulate Matter. Environ. Res. 63(1):26-38 (13 pages).

Lamsal, L.N.; Martin, R.V.; Parrish, D.D.; Krotkov, N.A., (2013). Scaling relationship for NO2 pollution and urban population size: a satellite perspective. Environ. Sci. Technol., 47(14): 7855-7861 (7 pages).

 Ma, Y.; Zhou, J.; Yang, S.; Yu, Z.; Wang, F.; Zhou, J., (2019). Effects of extreme temperatures on hospital emergency room visits for respiratory diseases in Beijing, China. Environ. Sci. Pollut. Res. Int., 26(3): 3055-3064 (10 pages).

Mayer, H., (1999). Air pollution in cities.  Atmos. Environ. (33): 4029-4037 (9 pages).

Maykut, N.N.; Lewtas, J.; Kim, E.; Larson, T.V., (2003). Source apportionment of PM2.5 at an urban IMPROVE site in Seattle, Washington. Environ. Sci. Technol., 37(22): 5135-5142 (8 pages).

MMA, (2014) Ministry of the Environment. Strategy of Atmospheric Decontamination Plans 2014-2018 (MMA for its acronym in Spanish), Republic of Chile (38 pages).

Molina, C.; Toro A, R.; Morales S, R.; Manzano, C.; Leiva-Guzmán, M., (2017). Particulate matter in urban areas of south-central Chile exceeds air quality standards. Air Qual. Atmos. Health. 10: 653-667 (15 pages).

Mott, J.A.; Mannino, D.M.; Alverson, C.J.; Kiyu, A.; Hashim, J.; Lee, T.; Falter, K.; Redd, S.C., (2005). Cardiorespiratory hospitalizations associated with smoke exposure during the 1997, Southeast Asian forest fires. Int. J. Hyg. Environ. Health. 208(1-2): 75-85 (11 pages).

Naeher, L.P.; Brauer, M.; Lipsett, M.; Zelikoff, J.T.; Simpson, C.D.; Koenig, J.Q.; Smith, K.R., (2007). Woodsmoke health effects: a review. Inhal. Toxicol., 19(1): 67-106 (40 pages).

Norris, G.; Young Pong, S.N.; Koenig, J.Q.; Larson, T.V.; Sheppard, L.; Stout, J.W., (1999). An association between fine particles and asthma emergency department visits for children in Seattle. Environ Health Perspect. 10: 489-493 (5 pages).

Orellano, P.; Quaranta, N.; Reynoso, J.; Balbi, B.; Vasquez, J., (2018). Association of outdoor air pollution with the prevalence of asthma in children of Latin America and the Caribbean: A systematic review and meta-analysis. J. Asthma. 55(11): 1174-1186 (13 pages).

Osseiran, N.; Lindmeier, C., (2018) 9 out of 10 people worldwide breathe polluted air, but more countries are taking action, World Health Organization. Geneva 2018.

Ostro, B.; Sanchez, J.M.; Aranda, C.; Eskeland, G.S., (1996). Air pollution and mortality: results from a study of Santiago, Chile. J. Expo. Anal. Environ. Epidemiol., 6(1): 97-114 (8 pages).

Ostro, B.D.; Eskeland, G.S.; Sanchez, J.M.; Feyzioglu, T., (1999). Air pollution and health effects: A study of medical visits among children in Santiago, Chile. Environ. Health. Perspect. 107(1): 69-73 (5 pages).

Peng, R.D., Dominici, F.  (2008) Statistical methods for environmental epidemiology with R: a case study in air pollution and Health, 1st. Ed., (144 pages).

Pino, P.; Oyarzun, M.; Walter, T.; von Baer, D.; Romieu, I., (1998). [Indoor air pollution in southeast Santiago, Chile]. Rev. Méd. Chile. 126(4): 367-374 (8 pages).

Pino, P.; Walter, T.; Oyarzun, M.; Villegas, R.; Romieu, I., (2004). Fine particulate matter and wheezing illnesses in the first year of life. Epidemiology. 15(6): 702-708 (7 pages).

Prieto, M.J.; Mancilla, P.; Astudillo, P.; Román, O., (2006). Exceso de morbilidad respiratoria en niños y adultos mayores en una comuna de Santiago con alta contaminación atmosférica por partículas. Rev. Méd. Chile., 135: 221-228 (8 pages).

 Pyne, S., (2014) World Fire: the culture of fire on Earth. (Pbk. ed.). Seattle: University of Washington Press (399 pages).

Roemer, W.; Hoek, G.; Brunekreef, B.; Clench-Aas, J.; Forsberg, B.; Pekkanen, J.; Schutz, A., (2000). PM10 elemental composition and acute respiratory health effects in European children (PEACE project). Pollution Effects on Asthmatic Children in Europe. Eur. Respir. J., 15(3): 553-559 (7 pages).

Roman, O.; Prieto, M.J.; Mancilla, P., (2004). [Atmospheric pollution and cardiovascular damage]. Rev. Méd Chile. 132(6): 761-767 (7 pages).

Sanhueza, P.; Vargas, C.; Jimenez, J., (1999). [Daily mortality in Santiago and its relationship with air pollution]. Rev. Méd. Chile. 127(2): 235-242 (8 pages).

Schreuder, A.B.; Larson, T.V.; Sheppard, L.; Claiborn, C.S., (2006). Ambient woodsmoke and associated respiratory emergency department visits in Spokane, Washington. Int. J. Occup. Environ. Health. 12: 147-153 (7 pages).

Sheppard, L.; Levy, D.; Norris, G.; Larson, T.V.; Koenig, J.Q., (1999). Effects of ambient air pollution on nonelderly asthma hospital admissions in Seattle, Washington, 1987-1994. Epidemiology. 10: 23-30 (8 pages).

SINCA, (2019) National Information System of Air Quality (SINCA for its acronym in Spanish) Ministry of the Environment, Republic of Chile.

Villalobos, A.M.; Barraza, F.; Jorquera, H.; Schauer, J.J., (2017). Wood burning pollution in southern Chile: PM2.5 source apportionment using CMB and molecular markers. Environ. Pollut., 225: 514-523 (10 pages).

Ward, D.J.; Ayres, J.G., (2004). Particulate air pollution and panel studies in children: a systematic review. Occup. Environ. Med., 61(4): 1-12 (12 pages).

Wyzga, R.E., (1978). The effect of air pollution upon mortality: a consideration of distributed lag models. J. Am. Stat. Assoc., 73(363): 463-472 (10 pages).

Xu, X.; Zborowski, J.V.; Arena, V.C.; Rager, J.; Talbott, E.O., (2008). Case-crossover analysis of air pollution and cardiorespiratory hospitalizations: using routinely collected health and environmental data for tracking: science and data. J. Public Health Manag. Pract., 14(6): 569-576 (8 pages).

Yañez, M.A.; Baettig, R.; Cornejo, J.; Zamudio, F.; Guajardo, J.; Fica, R., (2017). Urban airborne matter in central and southern Chile: Effects of meteorological conditions on fine and coarse particulate matter. Atmos. Environ., 161: 221-234 (14 pages).

Yu, O.; Sheppard, L.; Lumley, T.; Koenig, J.Q.; Shapiro, G.G., (2000). Effects of ambient air pollution on symptoms of asthma in Seattle-area children enrolled in the CAMP study. Environ Health Perspect 108: 1209-1214 (6 pages).

Zelikoff, J.T.; Chen, L.C.; Cohen, M.D.; Schlesinger, R.B., (2002). The toxicology of inhaled woodsmoke. J. Toxicol. Environ. Health. B Crit. Rev., 5(3): 269-282 (14 pages).

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