Peak Expiratory Flow Rate (PEFR) measures the airflow through the bronchi and thus the degree of obstruction in the airways. Exposure to high concentration of respirable suspended particulate matter (RSPM) decreases the PEFR and the decrease depends upon the exposure concentration of particles and exposure duration. The decrease in PEFR is found to be responsible for increase in blood pressure (BP). Relationship between increase in BP and reduction in PEFR is not exactly linear but it can be considered as liner. It is noticed that if PEFR is reduced to about 50% to 60% in that case sudden increase in BP is recorded and behaviour of BP rise has complex pattern. It is also an established fact that if PEFR is reduced more than 50%, this is treated as severe respiratory problem. There are many factors (i.e. smoking habits, medical treatment, physiology, etc.) which may govern the increase of BP in this condition. Estimated relationship is found as: ISBP = 0.213 + 0.263 IPEF, IDBP = 0.102 + 0.176 IPEF.