Data validation of non- invasive carboxyhemoglobin measurement in recipient blood using numerical modeling data: a case of Himalayan regions' households of Nepal

J Environ Health Sci Eng. 2021 May 19;19(1):39-57. doi: 10.1007/s40201-020-00574-w. eCollection 2021 Jun.

Abstract

Carbon monoxide decreases the oxygen carrying capacity of blood. As a result, it reduces the supply of oxygen into body cells and tissues including vital organs. It is poisonous during pregnancy as it leads to high risk for the mother and foetus. It causes the developmental disorders, cerebral anoxic lesions and even death of foetus. The major aim of this study is to validate the non- invasive % COHb monitored data with modelled data. IAQ instruments are administered to monitor CO concentraction and % COHb level in recipient's blood. Thus, the level of % COHb in blood is approximated using numerical modeling to validate the monitored data with modeled data. Twenty four hours average CO concentration with TCS house is found 8.65 ± 7.77 ppm, 7.39 ± 5.62 ppm, 6.69 ± 7.16 ppm, 4.76 ± 7.19 ppm, 4.48 ± 6.10 ppm in the order of case II > case I > case V > case III > case IV, respectively. Twenty four hours average CO concentration with ICS house is found 3.54 ± 4.41 ppm, 2.41 ± 3.93 ppm, 2.30 ± 2.24 ppm, 1.70 ± 2.93 ppm and 1.51 ± 1.24 ppm in the order of case I > case V > case II > case IV > case III respectively. The average CO concentration in breath by cook is found 3.75 (3.75 ± 2.35)ppm in ICS using house and 5.36 (5.36 ± 4.54)ppm in TCS using house with minimum 0.60 ppm and maximum 31.34 ppm. The CO exposure is found more than 13 h a day for TCS using house and 9 h a day for ICS using house. The average cook_CO exposure is found 5.36 (5.36 ± 4.54)ppm and 3.75 (3.75 ± 2.35)ppm in sampled house using TCS and ICS respectively. The average percentage COHb in sampled house using TCS and ICS is found 4.31 (4.3 ± 5.35) % and 3.72 (3.72 ± 2.67) % respectively. The correlation between numerical modelling of COHb with non- invasive COHb measurement is found significant i.e. P value <0.00001 establishing r2 value 0.95 and 0.97 for ICS and TCS using house respectively.

Keywords: Carbon monoxide; Carboxyhemoglobin; Improved cook stove; Indoor air quality; Traditional cook stove.