Prevalence and determinants of airflow limitation in urban and rural children exposed to cooking fuels in South-East Nigeria

Abstract

Background

Biofuels and other cooking fuels are used in households in low- and middle-income countries.

Aim

To investigate the impact of cooking fuels on lung function in children in urban and rural households in South-East Nigeria.

Methods

The multi-stage sampling method was used to enroll children exposed to cooking fuel in the communities. Lung function values FEV1, FVC and the FEV1/FVC ratio, were measured with ndd EasyOne^R spirometer. Airflow limitation was determined with FEV1/FVC Z-score values at −1.64 as the lower limit of normal (LLN5). The Global Lung Function Initiative 2012 software was used to calculate the lung function indices.

Results

The median age (range) of the 912 children enrolled was 10.6 years (6–18). Altogether, 468 (51.6%) children lived in rural areas. Seven hundred and thirty-seven (80.7%) were directly exposed to cooking fuels (418/737, 56.5% in rural areas). Wood and kerosene were the dominant fuels in rural and urban households. The respective mean Z-scores of the exposed children in rural and urban were zFEV1 −0.62, FVC −0.21, FEV1/FVC −0.83 and zFEV1 −0.57, zFVC −0.14, FEV1/FVC −0.75. Few (5.2%, 38/737) of the children had airflow limitation. Most of them (60.5%, 25/38) lived in the rural community; the lowest FEV1/FVC Z-scores were those of exposed to a combination of fuels.

Conclusion

Exposure to cooking fuels affects lung function in children with airway limitation in a small proportion, Control measures are advocated to reduce the morbidity related to cooking fuels exposure.

Keywords:

• Airflow limitation
• lung function
• cooking fuel exposure
• children
• Nigeria

Abbreviations:

• ANOVA, analysis of variance
• ATS/ERS, American Thoracic Society and European Respiratory Society
• BMI, body mass index
• DALY, disability-adjusted life years
• FER, forced expiratory ratio
• FEV₁, forced expiratory volume in one second
• FEV₆, forced expiratory volume in 6 s
• FEV₁/FVC, forced expiratory volume in one second and forced vital capacity
• FVC, forced vital capacity
• GLI, global lung function initiative
• HAP, household air pollution
• IQR, interquartile ratio
• LLN, lower limit of normal
• LMS, Lambda–Mu–Sigma
• LPG, liquefied petroleum gas
• MA, Massachusetts
• NHANES III, Third National Health and Nutrition Examination Survey
• NHREC, Nigeria Health Research and Ethics Committee
• PM, particulate matter
• SD, standard deviation
• SEC, socio-economic class
• SPSS, Statistical Package for Social Sciences
• WHO, World Health Organization

Acknowledgement

The authors acknowledge the immense contributions by Dr. Kenechukwu K. Iloh and Chimelu Okeke who helped in data collection. The traditional ruler of Ndeabo villages provided us with the base for our sample collection in his palace. All the children and their parents were very cooperative all through the study. We also express our profound gratitude to Late Dr. Philip H. Quanjer who graciously helped us with most of the statistical analyses.