Particulate Matter Exposure and Lung Function Assessment of Dairy Farm and Cattle Feed Manufacturing Workforce in Sahiwal, Pakistan

Abstract

The air quality within livestock facilities is adversely affected by elevated levels of dust, particulate matter, and microorganisms, posing significant health risks to both animals and farm workers. Studies show that exposure to bioaerosols, particulate matter (PM), and harmful gases raises the risk of respiratory diseases like asthma and chronic obstructive pulmonary disease COPD in individuals in these environments. The present study was carried out to investigate the pulmonic health effect of air borne particulate matter in Dairy Farm and Animal feed Manufacturing industry in Sahiwal, Pakistan. The air samples were collected using Potable low-volume Air sampler. The selected particulate matter includes PM2.5 and PM10. The highest PM concentrations were recorded in the Feed Manufacturing department (PM₂.₅ 149 ± 27 µg/m³; PM₁₀ 191 ± 23 µg/m³), while the lowest concentrations were observed in the Goat Pen (PM₂.₅ 27 ± 9 µg/m³) and Feed Dispatch (PM₁₀ 53 ± 22 µg/m³) departments. PM concentrations in all departments exceeded the threshold limit values (TLV) of 5 µg/m³ for PM₂.₅ and 15 µg/m³ for PM₁₀. Heavy Metals (Pb, Cd, Zn, and Cu) in collected Particulate Matter samples were analyzed through Atomic Absorption Spectrophotometer. The maximum concentrations detected were Pb 2.90 ppm, Cu 0.83 ppm, Zn 4.42 ppm, and Cd 0.016 ppm, all of which remained below the Occupational Exposure Limits (OELs) of Cu 200 ppm, Pb 50 ppm, Zn 2000 ppm, and Cd 2 ppm. For the evaluation of lung’s function test, among workers in dairy farm and Animal feed manufacturing industry, a digital handheld spirometer was used to conduct the test in 70 subject group and 30 control group and demographic data was also collected through questionnaire. Smokers are present in both the groups, but COPD patients were identified only in subject group where 21% of workers exhibited obstructive lung disease, 13% restrictive lung disease, 16% mixed lung disease, and 50% normal lung function, whereas the control group showed 20% obstructive lung disease, 10% restrictive lung disease, no mixed lung disease, and 70% normal lung function. The lung function test results were based on FEV1, FVC, FVC/FEV1, PEF. The maximum values observed were in sites of Cow Byre>Goat Pen>Feed Manufacturing sites. Obstructive lung diseases were prevailing in both the group. The mix-lung disease was only present in subject group. No HQ value exceeds the permissible limit set by US EPA. The Pearson correlation was conducted between heavy metals concentration and human lung function. A strong negative correlation occurred between zinc and FVC. Correlation analysis of heavyiii metals vs PM concentration indicated that Pb and Zn were moderately associated with PM2.5 concentrations, whereas PM 10 showed weak relationship with most heavy metals. A significant inverse correlation was observed between Pb and Zn in PM10 samples, indicating distinct emission sources