Methaemoglobin and Carboxyhaemoglobin Formation in Human Blood Due to NOx and CO Exposure: A Mathematical Model

Abstract

Combustion of Liquefied Petroleum Gas (LPG) in household kitchens results in the production of several harmful gases including Carbon Monoxide (CO) and Nitrogen Oxides (NOx). In the present work, an attempt has been made to investigate the effect of such gases on the percent oxygen saturation of blood and a nonlinear exponential model has been proposed based on reaction kinetics to quantify the amount of carboxyhaemoglobin and methaemoglobin formed in blood due to such exposures using a non-invasive technique. The model parameters have been estimated by using the experimental data obtained from exposure of the individuals to different concentrations of CO and NOx. Non-linear regression technique has been used in MATLAB® to optimise the objective function. The model has been validated for %COHb concentration in blood and corresponding data for ambient CO concentration reported in literature. The proposed model can be used to find the concentration of methaemoglobin and carboxyhaemoglobin formed in the blood for low exposures.