Indoor Air Quality

Indoor air quality (IAQ) refers to air quality inside closed environments, such as buildings and their surroundings, including private homes, offices, public buildings such as schools and hospitals, as well as mass transport systems. Poor IAQ may impact the health of individuals living or working in the building and its surroundings. Indoor air pollutants may include toxic gases (such as carbon monoxide [CO] and nitrogen oxides [NOx]), radon, volatile organic compounds (VOCs such as formaldehyde, benzene, toluene, and styrene), respirable particles (particulate matter [PM]), combustion products, pesticides, volatile flame retardants, tobacco smoke (secondhand and third-hand), biological pollutants (such as mold and bacteria), and other pollutants, such as asbestos fibers. Indoor biofuel cooking and heating are major potential sources of indoor air contamination. IAQ is mostly affected by three factors: (a) indoor sources of pollutants and materials, (b) the quality of ambient air entering the building, and (c) the air exchange rate between the indoor and the outdoor environment.

Poor IAQ has been associated with short-term health effects, such as upper and lower respiratory tract infections, allergic reactions, irritation of the eyes, nose, and throat; headaches, dizziness, and cognitive impairment; and also with long-term health effects, such as respiratory diseases (asthma, chronic obstructive pulmonary disease [COPD]), bronchitis, heart disease, and cancer. Exposure of young children to poor IAQ is associated with an increased risk of pneumonia and influenza.

Policy and Regulations

The Clean Air Law (2008) does not specifically refer to indoor air. Most of the regulations regarding indoor air (radon, ventilation requirements) are specified in planning and building standards.

Based on concerns regarding vapor intrusion of chlorinated organic compounds from contaminated land, in 2016 the Ministry of Environmental Protection (MoEP) published recommendations to prevent and measure indoor air contamination from vapor intrusion⁽⁵⁾.

In 2015, the Ministry of Health (MoH) mapped the main IAQ hazards that require special attention in Israel, such as exposure of the Bedouin population to household biomass combustion products, and exposure to radon. In 2017, MoH researchers published a position paper regarding the potential health implications of studying in schools and kindergartens in high-rise buildings due to poor IAQ. The researchers determined that IAQ should be given special attention during the planning and construction of high-rise buildings⁽¹⁾.

The Planning and Building Regulations passed in 1970 and most recently updated in 2008 require that buildings be planned and built in a way that prevents the accumulation of high radon levels. In addition, the regulations set maximum permissible indoor radon levels. The action level for radon concentrations in Israel is 200 Becquerel/m³ (Bq/m³), which is higher than the United States Environmental Protection Agency (EPA) action level (approximately 148.14 Bq/m³)⁽⁷⁾.

Israeli Standard 5281, which is a voluntary Green Building Standard, refers to sustainable building and addresses issues related to ventilation, the use of raw materials that do not emit toxic chemicals, and the quality of ambient air entering the building. The standard was updated in 2016 and currently refers to the reduction of VOCs and radioactive emissions from building materials. Of note, following a request from the MoH, the recommendation to install air ionizators was removed from the standard since there are no studies that support the contribution of air ionizators to enhanced IAQ.

The 2011 Israeli Standard 6210, "Ventilation for Acceptable Indoor Air Quality," which is based on the 2010 United States standard, defines permitted values for select indoor contaminants (including sulfur dioxide [SO₂], nitrogen dioxide [NO₂], carbon monoxide [CO], particulate matter of up to 10 micrometers [PM₁₀], and benzene). The standard was adopted by the National Committee for Planning and Construction as part of the mandatory Planning and Construction Standards, and is pending approval by the Ministry of Justice.

Data on Indoor Air Quality in Israel

A study by the MoEP and researchers from Hadassah Academic College analyzed data from 8,624 radon measurements conducted between 1991 and 2012. The percentage of rooms with radon  concentrations above the action level for homes in Israel (200 Bq/m³) ranged from 10% in radonprone geographical areas to 6% in geographical areas that are not radon-prone. Of note, there was a steady increase in radon concentrations between 1997 and 2012. As expected, the highest concentrations were found in radon-prone geographical areas, residential secure spaces (which have thick concrete walls), and ground-floor rooms⁽¹¹⁾.

According to the Global Burden of Disease database, the death rates and disability-adjusted life years (DALY) rates due to residential radon increased dramatically in Israel between the years 1990 to 2005, and have decreased in the last decade (Figure 1)⁽⁴⁾.

Due to concerns about excessive air pollution at bus platforms at the Central Bus Station in Jerusalem, the MoEP has been continuously monitoring levels of criteria air pollutants. The results indicate NO₂ levels in excess of warning values and high short-term concentrations of PM_2.5.

The MoEP publishes data from monitoring stations for PM_2.5, NO₂, and NOx at several transportation sites, such as the Jerusalem Central Bus Station, the Tel Aviv Central Bus Station, and several railway stations, mostly in central Israel. During the period of December 2014 to February 2015, the MoEP monitored 49 exceedances of PM_2.5 (during 82% of this period); 454 exceedances of NO₂ (during 42% of this period); and 1,189 exceedances of NOx (half hourly, during 42% of this period) at Platform 1 at the HaShalom Railway Station, apparently due to the train emissions and the proximity of the platform to the Ayalon highway⁽⁹⁾. During the period between March 2016 and June 2016, PM_2.5, NOx and NO₂ were measured at both the HaShalom and Yoseftal railway stations. There were 55 and 44 PM_2.5 exceedances, respectively (during  51% of the days when measurements were taken at HaShalom and during 57% of the days when measurements were taken at Yoseftal). There were many reported exceedances of NOx (half hourly) and NO₂. Of note, data are presented in comparison to air quality standards⁽⁶⁾.

Technion researchers recently conducted air pollution measurements and evaluated the passengers’ exposure to pollution in several locations: (a) the Jerusalem Central Bus Station and in the departing buses; and (b) the HaShalom Railway Station and in the departing trains. Extremely high average concentrations of ultrafine respiratory particles ([UFP], up to 1.9x10⁵ cm³) were measured at HaShalom train station platforms at peak hours. Low average UFP concentrations (below 1.5x10⁴ cm³) were measured in the intercity buses on the Jerusalem-Haifa route.

Research on Indoor Air Quality in Israel

Radon

Researchers from Ben-Gurion University of the Negev (BGU) and the Soreq Nuclear Research Center found that the average radon concentration in apartments in new buildings was statistically significantly higher than in old buildings, and that the average radon concentration in singlefamily houses was statistically significantly higher than in apartments in multi-story buildings. Higher radon concentrations in new buildings are likely related to the regulations mandating the construction of residential secure spaces that entered effect in the 1990s. The residential secure spaces' massive concrete walls, and the floor and the ceiling that can be hermetically sealed, are designed to protect its residents from a missile attack. The researchers used a model that takes into account the concentrations of the natural radionuclides in building materials, and the density and the thickness of the walls. According to their calculations, the overall annual exposure of the population of Israel to natural sources of ionizing radiation was 2 mSv, with ranges between 1.7 and 2.7 mSv^(2,3).

A Technion study analyzed results of natural radiation tests in concrete produced in Israel, including 109 concrete mixes produced commercially during 2012-2014. The average concentrations of radon were comparable to those in Mediterranean countries, such as Greece, Spain, and Italy. In addition, the average value of the radon emanation coefficient of concrete containing coal fly ash (FA) was lower than that of concrete mixes without FA⁽¹⁰⁾.

Indoor Biomass Combustion

Researchers from BGU and the MoH found that the use of open fire for cooking was highly prevalent among Bedouin women in southern Israel, and was more frequent among women who resided in temporary communities⁽¹²⁾.

Flame Retardants

Researchers at the Technion Center of Excellence in Exposure Science and Environmental Health (TCEEH) are studying the presence of flame retardants in dust that accumulates inside cars. Initial results show that polybrominated diphenyl ethers (PBDEs) were detected in most samples. No clear association between PBDE levels and vehicle manufacturer, model, or year was identified. Higher levels of PBDEs in car dust were observed in the summer than in the winter. Vehicles were found to possibly be an important microenvironment for PBDE exposure in the Mediterranean climate. These researchers are currently studying the presence of flame retardants in mattresses, including organophosphorous flame retardants.

Indoor-Outdoor Pollution Relationships

BGU researchers in collaboration with TCEEH are studying associations between indoor and outdoor air pollution and their health effects, during different diurnal periods and different seasons of the year in Haifa District municipalities.

Hebrew University of Jerusalem and Technion researchers are exploring ambient and indoor measurements of particulate matter concentrations in the city of Elad, which is near an active, high-production quarry. Continuous measurements are being conducted for a period of one year in private homes and in schools in the surrounding area, and in other locations in Israel, for comparison.

IAQ and Adverse Health Effects

Researchers at BGU are investigating the effect of exposure to indoor air pollution on type 2 diabetes by studying the effect of IAQ on a group of pregnant women living in Haifa and pregnant women living in Beer Sheva.

Progress since 2014

Environmental Health in Israel 2014 highlighted the need for collaboration among the MoEP, the MoH, and the Ministry of Education on a pilot study in schools, and the need for research on residential dust. There has been no progress with the pilot study in schools and only slight progress in research on residential dust.

Major Challenges

Some aspects of IAQ are handled by the MoEP (vapor intrusion) and the Standards Institute of Israel (the Green Building Standard, standards on formaldehyde emissions from wood, pending standards on flame retardants in mattresses). In addition, there are mandatory building standards in Israel regarding radon and building ventilation requirements. However, there is no central authority that handles IAQ. Consequently, IAQ is not a high priority issue and government budgets for research and monitoring in this field are limited. There are very limited data on the impact of consumer products and their components (such as VOCs used in mattress production, cleaning products, and paints) on IAQ.

IAQ is a challenging subject to study due to the broad range of factors that influence it, such as indoor materials, indoor activity, ventilation systems, and ambient air. There are considerable knowledge gaps regarding the health impacts of IAQ, including its effects on vulnerable populations and the relationship between ambient air pollution and IAQ. Since IAQ is dependent on climate and culture, there is a need for local research that focuses on IAQ in Israel.

Indoor combustion - primarily open-fire cooking inside the home, and use of wood or coal burning stoves - has a significant impact on IAQ. Indoor cooking on gas stoves in small unventilated spaces can lead to high NOx concentrations. Although the MoH published an infographic on IAQ and carbon monoxide (CO) pollution in 2016⁽⁸⁾, there is still a lack of awareness regarding the health impact of indoor combustion and the importance of IAQ. There is a need to formulate and publish clear, science-based recommendations for the public on ways to reduce exposure to indoor contaminants.

The latest data indicate that radon levels are higher in newer residential buildings with residential secure spaces. The MoEP, in collaboration with the MoH, is investigating health effects from radiation due to the use of fly coal ash in the concrete used for building residential secure spaces.

This chapter and all other chapters in the report was written by a team of scientists and professionals from the Ministry of Health, in collaboration with Environment and Health Fund.