Parth Sarathi Mahapatra1, Sumeet Jain2, Sujan Shrestha3, Shantibhusan Senapati4, Siva Praveen Puppala5. 1. International Centre for Integrated Mountain Development (ICIMOD), G.P.O. Box 3226, Kathmandu, Nepal. Electronic address: parth.mahapatra@icimod.org. 2. Institute of Life Sciences, Bhubaneswar, Odisha, India; Manipal University, Manipal, Karnataka, India. 3. International Centre for Integrated Mountain Development (ICIMOD), G.P.O. Box 3226, Kathmandu, Nepal. 4. Institute of Life Sciences, Bhubaneswar, Odisha, India. 5. International Centre for Integrated Mountain Development (ICIMOD), G.P.O. Box 3226, Kathmandu, Nepal. Electronic address: SivaPraveen.Puppala@icimod.org.
Abstract
BACKGROUND: Endotoxin associated with ambient PM (particulate matter) has been linked to adverse respiratory symptoms, but there have been few studies of ambient endotoxin and its association with co-pollutants and inflammation. OBJECTIVES: Our aim was to measure endotoxin associated with ambient PM10 (particulate matter with aerodynamic diameter<10μm) in summer 2016 at four locations in Chitwan, Nepal, and investigate its association with meteorology, co-pollutants, and inflammatory activity. METHODS: PM10 concentrations were recorded and filter paper samples were collected using E-samplers; PM1, PM2.5, black carbon (BC), methane (CH4), and carbon monoxide (CO) were also measured. The Limulus amebocyte lysate (LAL) assay was used for endotoxin quantification and the nuclear factor kappa B (NFκB) activation assay to assess inflammatory activity. RESULTS: The mean concentration of PM10 at the different locations ranged from 136 to 189μg/m3, and of endotoxin from 0.29 to 0.53EU/m3. Pollutant presence was positively correlated with endotoxin. Apart from relative humidity, meteorological variations had no significant impact on endotoxin concentration. NF-κB activity was negatively correlated with endotoxin concentration. CONCLUSIONS: To the best of our knowledge, this study provides the first measurements of ambient endotoxin associated with PM10 in Nepal. Endotoxin and co-pollutants were positively associated indicating a similar source. Endotoxin was negatively correlated with inflammatory activity as a result of a time-limited forest fire event during the sampling period. Studies of co-pollutants suggested that the higher levels of endotoxin related to biomass burning were accompanied by increased levels of anti-inflammatory agents, which suppressed the endotoxin inflammatory effect.
BACKGROUND: Endotoxin associated with ambient PM (particulate matter) has been linked to adverse respiratory symptoms, but there have been few studies of ambient endotoxin and its association with co-pollutants and inflammation. OBJECTIVES: Our aim was to measure endotoxin associated with ambient PM10 (particulate matter with aerodynamic diameter<10μm) in summer 2016 at four locations in Chitwan, Nepal, and investigate its association with meteorology, co-pollutants, and inflammatory activity. METHODS: PM10 concentrations were recorded and filter paper samples were collected using E-samplers; PM1, PM2.5, black carbon (BC), methane (CH4), and carbon monoxide (CO) were also measured. The Limulus amebocyte lysate (LAL) assay was used for endotoxin quantification and the nuclear factor kappa B (NFκB) activation assay to assess inflammatory activity. RESULTS: The mean concentration of PM10 at the different locations ranged from 136 to 189μg/m3, and of endotoxin from 0.29 to 0.53EU/m3. Pollutant presence was positively correlated with endotoxin. Apart from relative humidity, meteorological variations had no significant impact on endotoxin concentration. NF-κB activity was negatively correlated with endotoxin concentration. CONCLUSIONS: To the best of our knowledge, this study provides the first measurements of ambient endotoxin associated with PM10 in Nepal. Endotoxin and co-pollutants were positively associated indicating a similar source. Endotoxin was negatively correlated with inflammatory activity as a result of a time-limited forest fire event during the sampling period. Studies of co-pollutants suggested that the higher levels of endotoxin related to biomass burning were accompanied by increased levels of anti-inflammatory agents, which suppressed the endotoxin inflammatory effect.
Authors: Binaya Kc; Parth Sarathi Mahapatra; Dhruma Thakker; Amanda P Henry; Charlotte K Billington; Ian Sayers; Siva Praveen Puppala; Ian P Hall Journal: Ann Am Thorac Soc Date: 2020-06
Authors: Indhumathi Veerappan; Senthil Kumar Sankareswaran; Rajaguru Palanisamy Journal: Int J Environ Res Public Health Date: 2019-07-05 Impact factor: 3.390
Authors: Sagar Adhikari; Parth Sarathi Mahapatra; Chiranjibi Prasad Pokheral; Siva Praveen Puppala Journal: Int J Environ Res Public Health Date: 2020-01-15 Impact factor: 3.390