Full blood count and some haemorheologic variables of vendors exposed to liquefied petroleum (cooking) gas: a comparative study

Abstract

Introduction: Cooking gas in the form of liquefied petroleum gas is sold in gas stations and outlets by vendors who do not use personal protective equipment despite working in a high-risk environment hence they have a high exposure to inhalation of the chemicals in the gas. This study assessed the full blood count and haemorheologic variables of vendors exposed to liquefied petroleum gas. Methods: Forty gas vendors were enrolled from four gas stations in Calabar while forty apparently healthy individuals who do not work in gas-related jobs were recruited as control. Ethical approval was granted by the Cross River State Ministry of Health, Calabar. Permission to enroll workers was obtained from the management of gas stations while study subjects gave informed consent. A structured questionnaire was used to obtain demographic information and health history while blood pressure, weight and height were measured using standard instruments; the body mass index was calculated. The full blood count and haemorheologic variables were determined by standard methods. Data analysis was done using a student t-test on SPSS version 21 and a P value ≤0.05 was considered significant. Results: The mean age was 25.9±3.2 years and 26.5±6.5 years for the test and control groups with gas vendors being predominantly males (97.5%). Work duration of 97.5% of gas vendors was ≤5 years. Sixty percent of the control and 42.5% of the gas vendors engaged in regular exercise while 40% and 57.5% do not. Sixty-seven-point five percent (67.5%) of the control rarely go for medical checks and 27.5% had never had a medical check with only 2% who check often. For the gas vendors, 55% have never had a medical check while 45% of them rarely check. Also, 42.5% of the control have never or rarely checked their blood pressure while 15% check often; 62.5% of the gas vendors have never checked their blood pressure while 37.5% rarely check. There was a family history of hypertension for 2 (5%) of the control and none for the test group. Also, 1 (2.5%) of the gas vendors had a history of fainting episodes while 39 of them and the control did not. Only 10% and 20% of the gas vendors use nose mask and hand gloves with the use of overalls and safety boots being 40% for each. The body mass index of the control group (25.15kg/m2) was not different (P>0.05) from that of the test group (24.53kg/m2). Whereas the systolic blood pressure was higher for the gas vendors than the control (126.47mmHg and 120.32mmHg), the diastolic blood pressures were comparable (74.60mmHg versus 72.92mmHg). The full blood count shows the red blood cell count, haematocrit and haemoglobin of the gas vendors were significantly higher (P<0.05) than the control value while the mean corpuscular volume and mean corpuscular haemoglobin were comparable (P>0.05). Again, the mean corpuscular haemoglobin concentration and red cell distribution width standard deviation of the gas vendors were significantly higher (P<0.05) versus the control while the red cell distribution width coefficient of variation was comparable (P>0.05). The total white blood cell count and the absolute granulocyte and lymphocyte counts of the gas vendors were significantly higher (P<0.05) than the control value while the mixed leucocyte count was not different (P>0.05) between the two groups. The platelet count, mean platelet volume, platelet distribution width, plateletcrit, platelet large cell ratio and platelet large cell count were significantly higher (P<0.05) for the gas vendors when compared to the control. Relative plasma viscosity and fibrinogen concentration were significantly higher (P=0.030) when the test group was compared to the control. Conclusions: This study has demonstrated an increase in red cell, white cell and platelet parameters of vendors exposed to cooking gas as a probable response to an induced state of chronic inflammation. There is also impaired haemorheology as expressed by an increase in relative plasma viscosity and fibrinogen concentration with possible pre-disposition to cardiovascular disease as a consequence. Management of cooking gas stations and the vendors should be educated on the need to use personal protective equipment in order to reduce exposure to the components of cooking gas.