Particulate Matter 2.5 Causes Deficiency in Barrier Integrity in Human Nasal Epithelial Cells

PURPOSE: The effect of air pollution-related particulate matter (PM) on epithelial barrier function and tight junction (TJ) expression in human nasal mucosa has not been studied to date. This study therefore aimed to assess the direct impact of PM with an aerodynamic diameter less than 2.5 μm (PM2.5) on the barrier function and TJ molecular expression of human nasal epithelial cells. METHODS: Air-liquid interface cultures were established with epithelial cells derived from noninflammatory nasal mucosal tissue collected from patients undergoing paranasal sinus surgery. Confluent cultures were exposed to 50 or 100 µg/mL PM2.5 for up to 72 hours, and assessed for 1) epithelial barrier integrity as measured by transepithelial resistance (TER) and permeability of fluorescein isothiocyanate (FITC) 4 kDa; 2) expression of TJs using real-time quantitative polymerase chain reaction and immunofluorescence staining, and 3) proinflammatory cytokines by luminometric bead array or enzyme-linked immunosorbent assay. RESULTS: Compared to control medium, 50 and/or 100 µg/mL PM2.5-treatment 1) significantly decreased TER and increased FITC permeability, which could not be restored by budesonide pretreatment; 2) significantly decreased the expression of claudin-1 messenger RNA, claudin-1, occludin and ZO-1 protein; and 3) significantly increased production of the cytokines interleukin-8, TIMP metallopeptidase inhibitor 1 and thymic stromal lymphopoietin. CONCLUSIONS: Exposure to PM2.5 may lead to loss of barrier function in human nasal epithelium through decreased expression of TJ proteins and increased release of proinflammatory cytokines. These results suggest an important mechanism of susceptibility to rhinitis and rhinosinusitis in highly PM2.5-polluted areas.

Association of Exposure to PM2.5 and PM10 with DNA Damage in Exfoliated Buccal Mucosa Cells among Primary School Children Living Nearby Palm Oil Activity at Semenyih, Selangor

Abstract@#Introduction: Exposure of PM2.5 and PM10 released from combustion of biomass activity caused respiratory health among children. Objective: This study aims to determine the association between exposure of PM2.5 and PM10 with DNA damage in primary school children living nearby palm oil combustion activity at Semenyih. Methods: A cross sectional comparative study were conducted among Malay primary school children in school A located 2.7km from palm oil activity (N=82) and school B located about 40km away from the palm oil area (N=85). A standardized questionnaire were distributed to respondent’s parents. Concentrations of PM2.5 and PM10 were measured by using Dust Trak DRX Aerosol Monitor Model 8534 and Escort LC Personal Sampling Pump. Measurement of indoor and outdoor air pollutants were conducted in schools and home. Buccal cells were collected, which then followed by micronucleus assay. Results: Concentration of PM10 and PM2.5 at home of studied group were significantly higher compared to comparative group with p value (p=0.007) and (p=0.018) respectively. PM10 and PM2.5 of studied schools were significantly higher compared to comparative schools with p value (p=0.014) and (p=0.04) respectively. MN frequencies of studied group were significantly higher compared to comparative group (p=0.001). Significant difference of respiratory symptoms were found between two groups which are cough, phlegm, wheezing and chest tightness (p=0.001). There were significant correlation between PM10 with MN frequency of studied group and comparative group with r= 0.562; p=0.001. Conclusion: This study indicated that the exposure of PM10 and PM2.5 would increase the risk of having respiratory health symptoms and might induce the micronuclei formation among children who lived near palm oil activity area.

Progress in research of relationship between ambient air PM2.5 and lung diseases / 中华流行病学杂志

Fine Particulate Matter (PM2.5-particles with an aerodynamic diameter ≤2.5 μm)can penetrate deeply into the lung,deposit in the alveoli,and consequently impair lung function.Both short term and long term exposures to PM2.5 are associated with the incidence of respiratory diseases (e.g.asthma,chronic obstructive pulmonary disease,lung cancer).This paper summarizes the effects of ambient air PM2.5 exposure on human respiratory system revealed by epidemiological studies.

Progress in research of relationship between ambient air PM2.5 and lung diseases / 中华流行病学杂志

Fine Particulate Matter (PM2.5-particles with an aerodynamic diameter ≤2.5 μm)can penetrate deeply into the lung,deposit in the alveoli,and consequently impair lung function.Both short term and long term exposures to PM2.5 are associated with the incidence of respiratory diseases (e.g.asthma,chronic obstructive pulmonary disease,lung cancer).This paper summarizes the effects of ambient air PM2.5 exposure on human respiratory system revealed by epidemiological studies.

Numerical analysis on deposition of particulate matters in respiratory tract / 医用生物力学

Objective To study the regular pattern of inhalational particulate matter deposition in respiratory tract and its influencing factors during breathing by numerical simulation method. Methods Three-dimensional finite element model of normal human respiratory tract was established to simulate the airflow distributions in respiratory tract during inspiration. The particles were released at the entrance of nose or mouth to simulate the deposition process of suspended particles by inhaled airflow in respiratory tract. Different parameters such as particle diameter, particle density and flow rate of air volume were used for comparative analysis to investigate their functions as influencing factors when particle deposition happened in respiratory tract. Results The particles were mainly deposited in nasal threshold, nasal middle airway, nasopharynx, and bronchial inner wall of respiratory tract. The particle deposition rate increased with the parameters of particle diameter, particle density and air volume flow rate increasing. The influence of different parameters on the deposition rate was not the same. Conclusions The particle is mainly deposited at the site with complex geometry or at the position where path direction changes violently. Particle diameter, density and breathing airflow rate will affect the deposition rate in respiratory tract. These research findings will provide numerical references for the clinical assessment on risk of respiratory diseases caused by air pollution.

Distribution of Polycyclic Aromatic Hydrocarbons on Different Diametral Atmospheric Particulates / 环境与健康杂志

Objective To study the distribution of polycyclic aromatic hydrocarbons (PAHs)on different diameter atmospheric particulates in winter and summer respectively. Methods Atmospheric particulates in the atmosphere of Hengyang urban districts were collected using DFJ-1 model five-stage classification air sampler in the winter and summer. The contents of PAHs on different diameter atmosphere particulates were detected by GC-MS. Results The PAHs were found on different diameter atmosphere particles. The PAHs contents in the atmosphere in the winter and summer were 161.42?140.72 ng/m3. 52.3% and 63.3% PAHs distributed in the fine partioulates with dicameter ≤2.0 ?m in the summer and winter. Conclusion The PAHs contents in the atmosphere during winter were higher than that during summer,and the PAHs were mainly distributed in the fine particulates with diameter≤2.0 ?m. The distribution characteristics of different kinds of PAHs on different diameter atmospheric particulates were not unanimous. The distribution of PAHs in winter changed significantly.