Hospital indoor PM10/PM2.5 and associated trace elements in Guangzhou, China
Xinhua Wang1, Xinhui Bi, Guoying Sheng
1State Key Laboratory of Organic Geochemistry, Guangzhou Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou, PR China.
Abstract:
PM10 and PM2.5 samples were collected in the indoor environments of four hospitals and their adjacent outdoor environments in Guangzhou, China during the summertime. The concentrations of 18 target elements in particles were also quantified. The results showed that indoor PM2.5 levels with an average of 99 microg m(-3) were significantly higher than outdoor PM2.5 standard of 65 microg m(-3) recommended by USEPA [United States Environmental Protection Agency. Office of Air and Radiation, Office of Air Quality Planning and Standards, Fact Sheet. EPA's Revised Particulate Matter Standards, 17, July 1997] and PM2.5 constituted a large fraction of indoor respirable particles (PM10) by an average of 78% in four hospitals. High correlation between PM2.5 and PM10 (R(2) of 0.87 for indoors and 0.90 for outdoors) suggested that PM2.5 and PM10 came from similar particulate emission sources. The indoor particulate levels were correlated with the corresponding outdoors (R(2) of 0.78 for PM2.5 and 0.67 for PM10), demonstrating that outdoor infiltration could lead to direct transportation into indoors. In addition to outdoor infiltration, human activities and ventilation types could also influence indoor particulate levels in four hospitals. Total target elements accounted for 3.18-5.56% of PM2.5 and 4.38-9.20% of PM10 by mass, respectively. Na, Al, Ca, Fe, Mg, Mn and Ti were found in the coarse particles, while K, V, Cr, Ni, Cu, Zn, Cd, Sn, Pb, As and Se existed more in the fine particles. The average indoor concentrations of total elements were lower than those measured outdoors, suggesting that indoor elements originated mainly from outdoor emission sources. Enrichment factors (EF) for trace element were calculated to show that elements of anthropogenic origins (Zn, Pb, As, Se, V, Ni, Cu and Cd) were highly enriched with respect to crustal composition (Al, Fe, Ca, Ti and Mn). Factor analysis was used to identify possible pollution source-types, namely street dust, road traffic and combustion processes.
Insights
Indoor hospital air in Guangzhou had higher fine particulate matter (PM2.5) than outdoor standards. Outdoor infiltration, human activities, and ventilation significantly impacted indoor air quality, with elements originating mainly from outdoor sources.
Area of Science:
- Environmental Science
- Air Quality Monitoring
- Public Health
Background:
- Particulate matter (PM) poses significant health risks, especially in indoor environments.
- Hospital indoor air quality is critical for patient and staff well-being.
- Understanding PM sources and composition is vital for effective mitigation strategies.
Purpose of the Study:
- To investigate indoor and outdoor concentrations of PM10 and PM2.5 in Guangzhou hospitals.
- To determine the elemental composition of particulate matter.
- To identify the sources and influencing factors of indoor particulate pollution.
Main Methods:
- Collection of PM10 and PM2.5 samples from indoor and outdoor hospital environments.
- Quantification of 18 target elements within collected particulate matter.
- Statistical analysis including correlation analysis and factor analysis.
Main Results:
- Indoor PM2.5 concentrations (average 99 µg/m³) exceeded the USEPA standard (65 µg/m³).
- PM2.5 comprised 78% of indoor PM10, indicating a dominance of fine particles.
- Outdoor infiltration, human activities, and ventilation influenced indoor PM levels; elements primarily originated from outdoor sources.
- Anthropogenic elements (Zn, Pb, As, Se, V, Ni, Cu, Cd) were highly enriched, suggesting pollution from street dust, road traffic, and combustion.
Conclusions:
- Hospital indoor environments in Guangzhou experience elevated PM2.5 levels, exceeding outdoor standards.
- Outdoor air pollution significantly contributes to indoor particulate matter through infiltration.
- Human activities and ventilation systems also play a role in modulating indoor PM concentrations.
- Identifying specific elemental profiles aids in pinpointing pollution sources, crucial for targeted air quality management in healthcare settings.
