Characterization of Indoor Air Quality in Relation to Ventilation Practices in Hospitals of Lahore, Pakistan

Abstract

Temporal variations of particulate matter (PM) and carbon dioxide (CO2 ) in orthopedic wards and emergency rooms of different hospitals of Lahore, Pakistan were investigated. Hospitals were classified into two groups, I (centrally air-conditioned) and II (non-central air-conditioned) based on the ventilation system. Statistical analysis indicated significantly lower PM and CO2 levels in centrally air-conditioned hospitals in comparison to non-central air-conditioned. The low indoor-outdoor (I/O) ratio of PM2.5 in the ward and emergency rooms of group I (0.62, 0.45) as compared to group II (0.70, 0.83), respectively, suggested that indoor spaces equipped with central air-conditioning systems efficiently filter particulates as compared to non- central air conditioning systems. Apart from the ventilation type, increased visitor and doctors’ activities, and cleaning sessions were observed to contribute significantly to indoor air quality. This study adds up to the understanding of temporal variations in PM emissions and the role of ventilation systems in context of hospitals in the urban centers in Pakistan. The findings can inform the development of intervention strategies to maintain the appropriate air quality in health care built environment in developing countries.

Current approaches for preventing environment-associated contamination in healthcare facilities: a systematic literature review by open access database

“…In this way, there are 8 groups of articles: hospital ward, isolation room, Intensive Care Unit (ICU) room, various, operation room, emergency department, Biocontainment Unit (BCU), and alternative care sites, according to Table 4 . It is noteworthy that, in the case of the classification “various”, there are articles that address the entire floor of a hospital [ 18 ], which carried out a literature review article related to the subject [ 30 ], and that address more than one environment classification [ 19 , 25 ].…”

“…It is noteworthy that, in the case of the classification “various”, there are articles that address the entire floor of a hospital [ 18 ], which carried out a literature review article related to the subject [ 30 ], and that address more than one environment classification [ 19 , 25 ].…”

“…The other 6 articles address different subjects such as a fluorescent tracer particles experiment in a BCU unit [32]; a literature review on the impact that HVAC systems have on the well-being of patients [30]; good practices and strategies for HVAC system projects in ICU rooms [3]; an experimental study with field measurements to measure indoor air quality [25]; a dilution-based evaluation method for airborne infection risk [35]; and design strategies already utilized in biocontainment and in airborne infection isolation patient rooms and that improve infection control potential in alternative care sites [23].…”

“…Faced the increase in antibiotic-resistant pathogens, together with the emergence of new strains, Abraham et al (2021) [64] suggest the installation of copper surfaces in healthcare facilities, public transportation, public places, and food industries, considering that this material has continuing self-sanitising properties, working as a reducer or barrier to touch-transferred infections. HVAC systems [1-3, 13-15, 17-20, 22, 23, 25, 29, 30, 32, 33, 36, 37] HVAC systems play a key role in the risk of airborne infection [20] Importance of adequately positioning the patients (bed orientation) and the mobile air treatment units in the environment [20] Need to consider case by case when applying CFD simulation, since each room has its own parameters [1, 2, 13-22, 24, 26-29, 31, 33-37] Numerical (CFD) simulations and experiments can be used to visualise the airflow, the dispersion of aerosols generated by coughing, to visualise which areas are most susceptible to virus spread, to study and visualise the best arrangement and area of inlets and outlets of HVAC systems, and the best separation of spaces (partitions), among others [32] Possibility of using fluorescent tracer particles experiment to simulate airborne particle dispersion [2] Ventilation rate, inlet and outlet diffuser positions, and partitions between beds, among others, influence the airborne pathogen dispersion [23] Importance of modulate pressurization, direction of airflow, air exchange per hour, existence of air-handling systems with HEPA filters, UVC lighting, among others to reduce patient infection and exposure risk [17,25] According to ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers), indoor air quality is determined by the distribution of temperature, relative humidity, air velocity values, and pollution levels in the room environment. Ventilation type (central airconditioning system or non-central air conditioning system), increased visitor and doctors' activities, and cleaning sessions also interfere with indoor air quality [15] Necessity of increasing the rate of air change, decreasing recirculation of air, increasing the use of outdoor air and HEPA filters for disease and infection control [30] Indoor air temperature, relative humidity, indoor ventilation rate, air filtration system, differential pressure control, and mechanical strategies are related to patient medical outcomes [3] Necessity of increasing air supply and exhaust ventilation on toilets to avoid the fecal-oral transmission due to the droplets generated when flushing with the toilet lid open [27] The air exchange rate, the location of an infected patient, and the location of exhaust grilles in a ward influence the extent of the contamination.…”

Indoor Air Quality in Public Health Centers: A Case Study of Public Health Centers Located on Main and Secondary Roadsides, Bangkok

“…Furthermore, a case study in Bangkok regarding the relationship between indoor and outdoor PM2.5 concentrations in different conditions (open and closed ventilation systems) reported the PM2.5 concentrations in the closed ventilation area in each place in terms of Indoor/Ambient ratio (I/A ratio) ranged from 0.37 to 3.57, indicating that outdoor PM2.5 can enter the buildings through the ventilation system and infiltration (Sompornrattanaphan et al, 2018). Similarly, indoor PM2.5 concentrations in non- central air-conditioned hospitals were reported to be associated with outdoor concentrations indicating the impact of ambient air quality in urban centers on IAQ (Nimra et al, 2021). Lee et al (2020) studied the intervention effect on IAQ in hospitals and found that only PM2.5 concentrations decreased in rooms employing an air-cleaner.…”