Abstract P042: Use of Biomass Fuels for Cooking and Heating is Associated with Increased Non-communicable Disease Mortality: Golestan Cohort Study
Authors: Mitter Sumeet S , Islami Farhad , Pourshams Akram , Khademi Hooman , Kamangar Farin , Abnet Christian C , Brennan Paul , Boffetta Paolo , Vedanthan Rajesh , Malekzadeh Reza 
Published: July 2021

Introduction:
Exposure to indoor air pollution from burning of biomass fuels for heating and cooking is associated with an increase in mortality from respiratory illness in low- and middle-income countries. However, links to other non-communicable diseases has not been established.
Hypothesis:
We assessed the hypothesis that long-term exposure to biomass fuels increases mortality from heart disease, stroke, cancer and chronic lung disease.

Methods:
The Golestan Cohort Study enrolled 50045 individuals (42.4% men) in northern Iran. Data were collected on demographics; lifetime use of gasoline, kerosene, wood, and biomass (locally called pehen) for cooking and heating; lifetime use of tobacco, alcohol and opium; and medical history. Patients were followed through completion of the study or until death (total died = 2231). Hazard ratios (HRs) per every year of use of fuels were calculated using Cox proportional regression models for mortality due to all-causes, heart disease, stroke, cancer and respiratory illness based on length of exposure to a given fuel source, controlling for age, sex, rural living, socioeconomic status, body mass index, tobacco use, alcohol use, opiate use, diabetes mellitus and hypertension.

Results:
Pehen as a cooking fuel was significantly associated with mortality from all-causes (HR 1.005, 95% CI 1.001-1.010) and cancer (HR 1.009, 95% CI 1.001-1.017). Kerosene use was significantly associated with mortality from all-causes (HR 1.003, 95% CI 1.000-1.007) and heart disease (HR 1.007, 95% CI 1.001-1.012). Pehen as a heating fuel was associated with mortality due to all-causes (HR 1.005, 95% CI 1.001-1.009), stroke (HR 1.008, 95% CI 1.000-1.016) and cancer (HR 1.010, 95% CI, 1.002-1.017).

Conclusions:
In conclusion, indoor exposure to fuels such as pehen and kerosene is associated with increased mortality from non-communicable diseases. Further investigations from other low- and middle-income countries are warranted to comprehensively evaluate the health effects of biomass fuel use.

Table.

Fuel use and hazard ratios per year for death from main causes of mortality in Golestan, Iran

Cooking

Heating

Fuel
Mean duration (y) (SD)

Adjusted HR (95% CI)
*

Mean duration (y) (SD)

Adjusted HR (95% CI)
*

All causes (n = 2231)

Gas
29.09 (12.72)
0.998 (0.994-1.002)
3.54 (6.09)
0.997 (0.987-1.008)

Wood
27.50 (15.99)
1.001 (0.998-1.005)
28.29 (16.26)
1.002 (0.998-1.005)

Pehen/Other Organic
4.76 (12.01)
1.005 (1.002-1.010)
4.86 (12.04)
1.005 (1.001-1.009)

Kerosene/Diesel
7.88 (13.11)
1.003 (1.000-1.007)
30.53 (13.19)
1.001 (0.998-1.005)

Heart Disease (n = 755)

Gas
29.61 (12.82)
1.000 (0.994-1.007)
3.81 (6.36)
1.004 (0.987-1.022)

Wood
26.40 (15.54)
0.996 (0.990-1.001)
27.43 (15.84)
0.999 (0.993-1.004)

Pehen/Other Organic
4.47 (11.74)
1.003 (0.997-1.010)
4.48 (11.74)
1.003 (0.996-1.009)

Kerosene/Diesel
8.41 (13.03)
1.007 (1.001-1.012)
30.99 (13.01)
1.004 (0.998-1.009)

Cerebrovascular accident (n = 379)

Gas
28.44 (12.98)
0.991 (0.982-0.999)
3.61 (6.01)
0.987 (0.960-1.014)

Wood
29.16 (16.50)
1.005 (0.997-1.012)
29.88 (16.91)
1.005 (0.997-1.012)

Pehen/Other Organic
5.46 (13.04)
1.008 (0.999-1.016)
5.67 (13.22)
1.008 (1.000-1.016)

Kerosene/Diesel
8.62 (13.38)
1.007 (0.999-1.015)
30.93 (13.60)
1.003 (0.995-1.011)

Cancer (n = 471)

Gas
29.51 (12.21)
1.005 (0.997-1.013)
3.04 (5.74)
0.993 (0.968-1.019)

Wood
27.89 (15.67)
0.999 (0.992-1.007)
28.82 (15.61)
1.001 (0.993-1.008)

Pehen/Other Organic
5.65 (12.34)
1.009 (1.002-1.017)
5.79 (12.46)
1.010 (1.002-1.017)

Kerosene/Diesel
7.02 (12.86)
0.999 (0.992-1.007)
30.13 (13.31)
1.000 (0.993-1.007)

Respiratory Disease (n = 99)

Gas
28.38 (12.49)
0.993 (0.976-1.011)
3.78 (6.21)
1.022 (0.987-1.058)

Wood
28.71 (15.25)
1.002 (0.986-1.018)
29.48 (16.10)
1.002 (0.986-1.018)

Pehen/Other Organic
3.43 (10.42)
0.997 (0.977-1.018)
3.43 (9.33)
0.992 (0.971-1.014)

Kerosene/Diesel
7.93 (12.07)
0.999 (0.983-1.015)
29.73 (13.21)
0.992 (0.977-1.008)

*

Adjusted for age at enrollment, sex, rural living, socioeconomic status, body mass index, tobacco use, alcohol use, opiate use, and self-reported diabetes mellitus and hypertension