The state of indoor air quality in Pakistan—a review

Background and purpose: In Pakistan, almost 70% of the population lives in rural areas. Ninety-four percent of households in rural areas and 58% in urban areas depend on biomass fuels (wood, dung, and agricultural waste). These solid fuels have poor combustion efficiency. Due to incomplete combustion of the biomass fuels, the resulting smoke contains a range of health-deteriorating substances that, at varying concentrations, can pose a serious threat to human health. Indoor air pollution accounts for 28,000 deaths a year and 40 million cases of acute respiratory illness. It places a significant economic burden on Pakistan with an annual cost of 1% of GDP. Despite the mounting evidence of an association between indoor air pollution and ill health, policy makers have paid little attention to it. This review analyzes the existing information on levels of indoor air pollution in Pakistan and suggests suitable intervention methods. Methods: This review is focused on studies of indoor air pollution, due to biomass fuels, in Pakistan published in both scientific journals and by the Government and international organizations. In addition, the importance of environmental tobacco smoke as an indoor pollutant is highlighted. Results: Unlike many other developing countries, there are no long-term studies on the levels of indoor air pollution. The limited studies that have been undertaken indicate that indoor air pollution should be a public health concern. High levels of particulate matter and carbon monoxide have been reported, and generally, women and children are subject to the maximum exposure. There have been a few interventions, with improved stoves, in some areas since 1990. However, the effectiveness of these interventions has not been fully evaluated. Conclusion: Indoor air pollution has a significant impact on the health of the population in Pakistan. The use of biomass fuel as an energy source is the biggest contributor to poor indoor air quality followed by smoking. In order to arrest the increasing levels of indoor pollution, there is a dire need to recognize it as a major health hazard and formulate a national policy to combat it. An integrated effort, with involvement of all stakeholders, could yield promising results. A countrywide public awareness campaign, on the association of indoor air pollution with ill health, followed by practical intervention would be an appropriate approach. Due to the current socioeconomic conditions in the country, development and adoption of improved cooking stoves for the population at large would be the most suitable choice. However, the potential of biogas as a fuel should be explored further, and modern fuels (natural gas and LPG) need to be accessible and economical. Smoking in closed public spaces should be banned, and knowledge of the effect of smoking on indoor air quality needs to be quantified. © 2010 Springer-Verlag

Indoor Air Quality

[Excerpt] “Indoor air quality or IAQ” is what we experience as the temperature, humidity, ventilation, and chemical or biological contaminants of the air inside non-industrial buildings, such as schools, offices, hotels, or banks – environments typically considered pristine when compared with industrial settings. In today’s world, we spend about 90% of our day indoors and the pollution indoors can be 2 to 5 times – and occasionally more than 100 times -- higher than outdoor levels. After all, we humans exhale (and otherwise produce) the endproducts of metabolism. We shed hair and dander. We have in our buildings all kinds of textiles, equipment, paper, cleaning products, and maintenance activities – so the air can be very different from “fresh outside air.” We notice this difference – sometimes simply as odors and sometimes as symptoms such as: • irritation of eyes, nose, or throat • dry mucous membranes and skin • erythema – reddening or flushing of the face or skin • mental fatigue, headache, sleepiness • airway infections, cough • hoarseness, wheezing • nausea, dizziness • hypersensitivity reactions. Studies of buildings have indicated that poor IAQ can cause health problems, affect occupants’ productivity and reduce learning, as well as have liability issues and cause poor public relations – a building gets a bad reputation which affects leasing and purchasing

Optimization on fresh outdoor air ratio of air conditioning system with stratum ventilation for both targeted indoor air quality and maximal energy saving

Stratum ventilation can energy efficiently provide good inhaled indoor air quality with a proper operation (e.g., fresh outdoor air ratio). However, the non-uniform CO2 distribution in a stratum-ventilated room challenges the provision of targeted indoor air quality. This study proposes an optimization on the fresh outdoor air ratio of stratum ventilation for both the targeted indoor air quality and maximal energy saving. A model of CO2 concentration in the breathing zone is developed by coupling CO2 removal efficiency in the breathing zone and mass conservation laws. With the developed model, the ventilation parameters corresponding to different fresh outdoor air ratios are quantified to achieve the targeted indoor air quality (i.e., targeted CO2 concentration in the breathing zone). Using the fresh outdoor air ratios and corresponding ventilation parameters as inputs, energy performance evaluations of the air conditioning system are conducted by building energy simulations. The fresh outdoor air ratio with the minimal energy consumption is determined as the optimal one. Experiments show that the mean absolute error of the developed model of CO2 concentration in the breathing zone is 1.9%. The effectiveness of the proposed optimization is demonstrated using TRNSYS that the energy consumption of the air conditioning system with stratum ventilation is reduced by 6.4% while achieving the targeted indoor air quality. The proposed optimization is also promising for other ventilation modes for targeted indoor air quality and improved energy efficiency

A comparison of different ventilation strategies for dwellings in terms of airflow rates and airflow paths

The context of ventilation in Belgian dwellings has changed since the publication of the Belgian standard NBN D 50-001:1991. Due to the higher energy performance of these dwellings, ventilation plays nowadays a more essential role in maintaining a good indoor air quality. Therefore, new rules for improved ventilation strategies are needed to accomplish high energy-efficient ventilation while providing a good indoor air quality. A first step is to compare different ventilation strategies, including strategies that don’t comply with the current standard, in terms of airflow rates and airflow paths. This comparison also includes the influence of demand controlled ventilation. This paper covers a simulation study using multi-zone airflow and contaminant transport calculation software (CONTAM) which compares the performances of the different ventilation strategies in terms of indoor air quality and average airflow rates. The evaluation of the indoor air quality is based on the exposure of the occupants to CO2 and VOC and on the relative humidity in the rooms. The different ventilation strategies can achieve a comparable indoor air quality, including the strategies not conform to the Belgian standard. However, some strategies require up to twice the airflow rate than others

Correlation of the Indoor Air Quality Santriwati Dormitory with Acute Respiratory Infection at Raudhatul Ulum Islamic Boarding Schools and Al-ittifaqiah Islamic Boarding Schools in Ogan Ilir on 2015

Background: The high number of acute respiratory infection found in two islamic boarding schools specifically at Raudhatul Ulum Islamic Boarding Schools are 178 cases and 231 cases at Al-Ittifaqiah. Method: It was an observational research using cross-sectional design. Research sites at Raudhatul Ulum Islamic Boarding Schools and Al-Ittifaqiah Islamic Boarding Schools in Ogan Ilir. The population research was all santriwati both Islamic boarding schools that total sample 72 santriwati. The dependent variable in this study was santriwati incidence of respiratory infection, the independent variable was the physical quality of the air (temperature, lighting, humidity, rate of ventilation), the quality of biological air (number of bacterial air), residential density, sanitize behavior, and the behavior of openning window.The sample collection technique namely random sampling with the methods of sampling stratified. Data would be analyzed using chi square test. Result: The research result showed that there is significant correlation between temperature p= 0,013, residential density p= 0,003, sanitize behavior p= 0,001, and the behavior of opening a window p= 0,012 on the acute respiratory infection. There is no significant relationship in lighting p= 0,401, humidity p= 0,170, ventilation rate p= 0,489, and the germ air p= 0,170 as the acute respiratory infection. Conclusion: This research concluded that temperatur, residential density, sanitize behavior, and the behavior of opening window have significant correlation

Outdoor-indoor air pollution in urban environment: challenges and opportunity

With the continual improvement in our quality of life, indoor air quality has become an important area of concern in the twenty-first century. Indoor air quality is affected by many factors including the type and running conditions of indoor pollution sources, ventilation conditions, as well as indoor activities. Studies revealed that the outdoor environment is also an important factor that cannot be neglected for indoor air quality studies. In this review, the indoor and outdoor air pollution relationships obtained from different studies are discussed in order to identify the key factors affecting the indoor air quality. As climate change is recognized as imposing impacts on the environment, how it affects the indoor air quality and the health impacts to the occupants will be evaluated in this paper. The major challenges and opportunities in indoor/outdoor air pollution studies will be highlighted.published_or_final_versio

Health effects of home energy efficiency interventions in England: a modelling study

Objective: To assess potential public health impacts of changes to indoor air quality and temperature due to energy efficiency retrofits in English dwellings to meet 2030 carbon reduction targets. Design: Health impact modelling study. Setting: England. Participants: English household population. Intervention: Three retrofit scenarios were modelled: (1) fabric and ventilation retrofits installed assuming building regulations are met. (2) As with scenario (1) but with additional ventilation for homes at risk of poor ventilation. (3) As with scenario (1) but with no additional ventilation to illustrate the potential risk of weak regulations and non-compliance. Main Outcome: Primary outcomes were changes in quality adjusted life years (QALYs) over 50 years from cardiorespiratory diseases, lung cancer, asthma and common mental disorders due to changes in indoor air pollutants, including: second-hand tobacco smoke, PM2.5 from indoor and outdoor sources, radon, mould, and indoor winter temperatures. Results: The modelling study estimates showed that scenario (1) resulted in positive effects on net mortality and morbidity of 2,241 (95% credible intervals (CI) 2,085 to 2,397) QALYs per 10,000 persons over 50 years due to improved temperatures and reduced exposure to indoor pollutants, despite an increase in exposure to outdoor–generated PM2.5. Scenario (2) resulted in a negative impact of -728 (95% CI -864 to -592) QALYs per 10,000 persons over 50 years due to an overall increase in indoor pollutant exposures. Scenario (3) resulted in -539 (95% CI -678 to -399) QALYs per 10,000 persons over 50 years due to an increase in indoor exposures despite targeting. Conclusions: If properly implemented alongside ventilation, energy efficiency retrofits in housing can improve health by reducing exposure to cold and air pollutants. Maximising the health benefits requires careful understanding of the balance of changes in pollutant exposures, highlighting the importance of ventilation to mitigate the risk of poor indoor air quality

A conceptual approach to determine optimal indoor air quality: A mixture experiment method

Achieving good air quality in large residential and commercial buildings continues to be a top priority for owners, designers, building managers and occupants. The challenge is even greater today. There are many new materials, furnishing, products and processes used in these buildings that are potential source of contaminations and pollutants. A common problem to the indoor and outdoor environments is that of exposure to mixtures of air pollutants. Researchers and practitioners tend to focus on single pollutants (e.g. CO2, PM2.5) ignoring the mixtures combined effect. Fashion dictates to study the pollutant most thoroughly talked about. Distinguishing the effects of such co-pollutants is difficult. The conclusions about which component of a mixture is actually producing a given effect are sometimes less soundly based than could be wished. It is especially important in considering the indoor mixture of air pollutants as this mixture may be entirely different from those found outside. Exposures to raised levels of air pollutants can damage health, for example carbon monoxide can cause death and significant lasting disability. Controlling levels of indoor air pollutants is therefore important, as good indoor air quality is essential to health. There are three strategies for achieving acceptable indoor air quality: ventilation, source control and cleaning/filtration. Depending on the building and the specific characteristics of the location, these strategies can be used singly or in combination. However, mixture experiment would throw more light and understanding into indoor air composition and interaction properties and the combine effects it has on human health. Mixture experiments have been used extensively in other industries, for example the pharmaceutical industry and the agrochemical industry, for the production of tablets and the control of plant diseases and pests. Developing a mixture model for the internal microclimate for a particular building type and/or location may help us in developing better indicators, standards and policy document in the near future, when the levels of pollutants concentration can be successfully predicted

Indoor Air Quality Assessment: Comparison of Ventilation Scenarios for Retrofitting Classrooms in a Hot Climate

Current energy e ciency policies in buildings foster the promotion of energy retrofitting of the existing stock. In southern Spain, the most extensive public sector is that of educational buildings, which is especially subject to significant internal loads due to high occupancy. A large fraction of the energy retrofit strategies conducted to date have focused on energy aspects and indoor thermal comfort, repeatedly disregarding indoor air quality criteria. This research assesses indoor air quality in a school located in the Mediterranean area, with the objective of promoting di erent ventilation scenarios, based on occupancy patterns and carbon dioxide levels monitored on site. Results show that manual ventilation cannot guarantee minimum indoor quality levels following current standards. A constant ventilation based on CO2 levels allows 15% more thermal comfort hours a year to be reached, compared to CO2-based optimized demand-controlled ventilation. Nevertheless, the latter ensures 35% annual energy savings, compared to a constant CO2-based ventilation, and 37% more annual energy savings over that of a constant ventilation rate of outdoor air per person