Exposure of bakery and pastry apprentices to airborne flour dust using PM<Subscript>2.5</Subscript> and PM<Subscript>10</Subscript>personal samplers

Background  

This study describes exposure levels of bakery and pastry apprentices to flour dust, a known risk factor of occupational asthma.     

Polycyclic aromatic hydrocarbons in PM<Subscript>10</Subscript>, PM<Subscript>2.5</Subscript> and PM<Subscript>1</Subscript> particle fractions in an urban area

Inhalation of atmospheric polycyclic aromatic hydrocarbons (PAHs) bound to particulate matter can have adverse effects on human health. Particle size plays an important role in assessing health risks. The aim of this study was to compare concentrations of PAHs in different particle fractions. Measurements of PAHs were carried out in Zagreb, the capital of Croatia (~?790,000 inhabitants). The measuring station was located in the northern, residential part of Zagreb, close to a street with modest traffic density. Twenty-four-hour samples of PM₁₀, PM_2.5 and PM₁ particle fraction were collected on quartz filters using a low-volume sampler from about 50 m³ of air. Three fractions were collected from January to December 2013. The analysis was performed using high-performance liquid chromatography (HPLC) with a fluorescence detector and time-programmed changes in excitation and emission. Comparison of PAH content in PM₁₀ and PM_2.5 particle fractions revealed that more than 80% of PAHs measured in winter were bound to the smaller particle fraction (PM_2.5), except for Chry, IP and DahA. In summer, more than 60% of measured PAHs were bound to PM_2.5 particles, except for DahA, while in spring, more than 50% of measured PAHs were bound to PM_2.5 particles, except for Flu, BaP and BbF. Furthermore, comparing PAH content in PM₁ and PM_2.5 fractions, we found that most PAHs were bound to particle fraction PM₁, and the percentage of PAHs in PM₁ was the highest in winter (more than 90%). Factor analysis showed that most of the PAHs bound to PM₁₀, PM_2.5 and PM₁ probably had identical sources in winter, spring and summer (house heating and traffic), and the only significant difference in origin was found in autumn for PAHs bound to PM_2.5 and PM₁ fractions.     

Inhalation exposure of children to indoor PM<Subscript>10</Subscript> and associated metals during river-dust episodes

Three exposure groups (high exposure, low exposure, and control), using six elementary schools in Yulin County, were selected to study the impacts of aeolian river-dust on school children’s exposure to PM₁₀ and associated metals. One classroom and about five school-aged children’s houses for each school were chosen to collect indoor PM₁₀ during the river-dust episodes (RDEs) and non-river-dust episodes (NRDEs). The results indicated that the river-dust episodes had significant impacts on the school-aged children’s exposure to concentrations of PM₁₀ and metals, especially in the high exposure group. For the Ni and Mn metals, the 8-h school exposure concentrations during RDEs were both higher than the standards suggested by the California Environmental Protection Agency. Three interventions for protecting school children from being affected by the river dust during RDEs are suggested in this study. Among the three interventions, children who have a day off of school during RDEs can result in the greatest decrease in the exposure levels of PM₁₀ and associated metals.     

Investigating indoor concentrations of PM<Subscript>10</Subscript> in an underground loading dock in Malaysia

Risky air contaminants including PM₁₀ can accumulate inside underground confined loading docks because of the enclosed nature and limited contacts of loading docks with ambient air. Exposure to PM₁₀ can increase morbidity and mortality rates. Hence, this study aimed to investigate and model PM₁₀ concentrations in an underground loading dock located at Kuala Lumpur city center, Malaysia. For this purpose, a real-time air quality monitoring instrument was used for measuring PM₁₀ concentrations for 20 consecutive weeks starting from November 8, 2014. After that, the Statistical Package for Social Sciences (SPSS) software was used to analyze measured PM₁₀ concentrations through series of statistical analyses, whereas MATLAB R2013a was employed for developing prediction models of future PM₁₀ concentrations. Moreover, PM₁₀ temporal variation was examined using time series plots. The results showed that short-term PM₁₀ concentrations did not exceed the Malaysian indoor allowable limit of 150 μg/m³. Despite that, PM₁₀ had 8 % probability of exceedance of WHO standard concentration of 50 μg/m³. This indicates that the occupants will be under the risk of prolonged exposure to PM₁₀ even at low concentrations. The results confirmed a strong correlation between PM₁₀ concentrations and diesel-powered vehicles flow. Contrarily, the flow of gasoline-powered vehicles was poorly correlated. Finally, future daily-averaged PM₁₀ concentrations were predicted for the three weekdays that followed the measurement period using single exponential smoothing. The obtained accuracy was at 70 % of measured PM₁₀ concentrations. Future hourly-averaged PM₁₀ concentrations were estimated using single linear regression with an accuracy of 53 %.     

Indoor and outdoor air quality analysis for the city of Nablus in Palestine: seasonal trends of PM<Subscript>10</Subscript>, PM<Subscript>5.0</Subscript>, PM<Subscript>2.5</Subscript>, and PM<Subscript>1.0</Subscript> of residential homes

Nablus city is an important urban and industrial center in the West Bank, Palestine. The topography of the city, combined with multiple sources of air pollution, creates a potential air quality problem that might affect human health. The indoor and outdoor particle concentration distributions of PM₁₀, PM_5.0, PM_2.5, and PM_1.0 were measured using a Grimm aerosol spectrometer from December 2014 to November 2015, at four roadsides and four urban homes in Nablus. The results of the annual averages of PM₁₀ and PM_2.5 concentrations were found to be at least three times higher than that of the European Air Quality Standards both in indoors and outdoors. The difference in the results between both the roadside and the urban areas was attributed to human and industrial activities in Nablus. The results revealed that the highest concentrations of the particulate matters are during summer, especially June and July, in the roadside areas due to heavy industrial activities during these months. The same behavior was noticed for urban areas during summer and due to other human activities. The results of indoor/outdoor (I/O) ratios were found to be less than, but very close to, 1 for both roadside and urban areas in summer and winter months. In winter times, areas with poor ventilation indicated the existence of additional sources of PM within the indoor environments, especially when smoking cigarettes and using fuel-based heaters such as fireplaces gas and kerosene heaters.     

Practicalities of mapping PM<Subscript>10</Subscript> and PM<Subscript>2.5</Subscript> concentrations on city-wide scales using a portable particulate monitor

Fine particulate matter is considered to be the most significant ambient air pollutant in terms of potential health impacts. Therefore, it is important that regulators are able to accurately assess the exposure of populations to PM₁₀ and PM_2.5 across municipal areas. We report on the practicalities of using a laser light scattering portable particulate monitor (Turnkey Instruments DustMate), in combination with a GPS, to map PM₁₀ and PM_2.5 concentrations on city-wide scales in Newcastle upon Tyne/Gateshead (UK), during a series of walking surveys. A heated inlet is necessary to remove moisture droplets from the sampled air prior to analysis by the instrument, though this also results in the loss of volatile particulate components, particularly from the PM_2.5 fraction. A co-location calibration study was carried out with a reference urban background Tapered Element Oscillating Micro-Balance/Filter Dynamics Measuring System (TEOM-FDMS) system in Newcastle that is part of the UK’s Automatic Urban and Rural Network (AURN) of air quality monitoring stations. For PM₁₀, orthogonal regression of the DustMate against TEOM-FDMS data gave a slope and intercept of 1.02?±?0.06 and ?3.7?±?1.2, respectively (R ²?=?0.73), whereas for PM_2.5, the respective values were 0.78?±?0.06 and ?0.63?±?0.55 (R ²?=?0.79). These parameters are comparable to literature calibration studies using this technology. There was good agreement between simultaneous samples taken using two DustMate instruments: for PM₁₀, a slope and intercept of 1.05?±?0.03 and 0.36?±?0.5, respectively (R ²?=?0.73), were obtained, whereas for the PM_2.5, the respective values were 0.79?±?0.01 and 0.19?±?0.06 (R ²?=?0.86). Correction factors based on the slope and intercepts obtained from the calibration exercise were applied to raw data collected from the DustMate. An annually-normalised correction procedure was then used to account for different background particulate concentrations on different sampling days. These corrected PM₁₀ and PM_2.5 concentrations and corresponding GPS coordinates were displayed on a base map using Google Fusion Tables and Google Earth Professional. Almost all areas surveyed in Newcastle/Gateshead were well below the EU Air Quality Standards for PM₁₀ and PM_2.5.     

Characteristics of PM<Subscript>2.5</Subscript> and its chemical constituents in Beijing,Seoul, and Nagasaki

Ambient fine particulate matter (PM_2.5) samples were collected from September 2013 to May 2015 in three cities in East Asian countries (Beijing, China; Seoul, South Korea; and Nagasaki, Japan) in order to analyze the spatiotemporal trends of PM_2.5 chemical constituents including organic matter (OM), elemental carbon (EC), water-soluble inorganic ions (NO₃^?, SO₄^2?, and NH₄⁺), and trace elements. The average PM_2.5 mass concentration were 125?±?6.80 μg m^?3, 44.6?±?0.84 μg m^?3, and 17.4?±?0.37 μg m^?3 in Beijing, Seoul, and Nagasaki, respectively. Higher carbonaceous concentrations were observed during winter in Beijing and Seoul, while higher concentrations were found during spring in Nagasaki. The highest seasonal averages of organic carbon (OC) to EC ratios were found during spring in Beijing, winter in Seoul, and fall in Nagasaki. The concentrations of secondary OC and its ratio to OC were high during fall and winter. For ion species, NO₃^? was dominant in Beijing and Seoul, while SO₄^2? was dominant in Nagasaki. Increased contributions of mobile sources in Beijing and Seoul were observed, with higher NO₃^?/SO₄^2? ratios than those in Nagasaki. Three groups of air masses were found for the three cities using cluster analyses based on 72-h backward trajectories. The cluster from the Bohai economic zone had the highest concentration of PM_2.5 for Beijing. For Seoul, a cluster that originated from the Yellow Sea near an industrial area in Liaoning Province and passed through a highly polluted industrial area in southwestern Seoul had high PM_2.5 concentrations. A long-range transported cluster that originated in and crossed through heavily industrialized areas in China and South Korea for Nagasaki had higher ion species concentrations. The results of this study are useful to identify the current levels of PM_2.5 and its chemical properties to establish a control plan for PM_2.5 for Northeast Asia, including China, South Korea, and Japan.     

Characteristic and Source of Atmospheric PM<Subscript>10</Subscript>- and PM<Subscript>2.5</Subscript>-bound PAHs in a Typical Metallurgic City Near Yangtze River in China

The characteristics of atmospheric PM₁₀- and PM_2.5-bound polycyclic aromatic hydrocarbons (PAHs) were investigated in Tongling city, China. Results showed that the total concentrations of PM₁₀- and PM_2.5-bound PAHs exhibited distinct seasonal and spatial variability. The metallurgic sites showed the highest PAH concentrations, which is mainly attributed to the metallurgic activities (mainly copper ore smelting) and coal combustion as the smelting fuel. The rural area showed the lowest concentrations, but exhibited significant increase from summer to autumn. This seasonal fluctuation is mainly caused by the biomass burning at the sites in the harvest season. The diagnostic ratio indicated that the main PAHs sources were vehicle exhausts, coal combustion and biomass burning. The total BaP equivalent concentration (BAP-TEQ) was found to be maximum at DGS site in winter, whereas it was minimum at BGC site in summer. Risk assessment indicates that residential exposure to PAHs in the industrial area, especially in the winter season, may pose a greater inhalation cancer risk than people living in living area and rural area.     

Relationship Between 4-Day Air Mass Back Trajectories and Metallic Components in PM<Subscript>10</Subscript> and PM<Subscript>2.5</Subscript> Particle Fractions in Zagreb Air,Croatia

This paper presents a study on the relationship between trace metal concentrations and the state of the atmosphere at the Croatian EMEP station Puntijarka, Zagreb. PM₁₀ and PM_2.5 particle fractions are hazardous in terms of morbidity and hospitalization due to cardiovascular and respiratory diseases, and in terms of total mortality. In Zagreb, PM₁₀ and PM_2.5 monitoring started on a daily basis at a sampling site located in the northern, residential part of the city. Trace metal concentrations were determined from daily samples. Air mass back trajectories were used to determine particulate air pollution from local and remote sources. The investigation has shown a statistically significant association between air mass back trajectories and metallic air concentration levels.     

Two notable features in PM<Subscript>10</Subscript> data and analysis of their causes

Hourly PM₁₀ mass concentrations were collected from 25 air quality monitoring stations in Seoul, Korea. Sixteen years of data, from 2000 to 2015, were analyzed. During that time, the annual average PM₁₀ concentrations declined almost linearly at a rate of ?1.98 μg m^?3 year^?1. The number of high PM₁₀ days declined faster than did the number of low PM₁₀ days. This indicates that the bulk of the annual average PM₁₀ mass concentration reduction was high-level PM₁₀ concentrations. Further analysis of this data revealed two interesting points. First, though the annual average PM₁₀ concentrations clearly lowered for period 1 (from 2000 to 2012; ?2.28 μg m^?3 year^?1), they remained almost unchanged at a virtually constant value for period 2 (from 2012 to 2015; ?0.02 μg m^?3 year^?1). Second, annual average PM₁₀ concentrations showed a large spatial concentration gradient among all monitoring stations in the early 2000s. However, the spatial concentration gradient got gradually smaller until reaching a nearly no-gradient, uniform concentration among all monitoring stations from 2010 onward. Clear PM₁₀ concentration reduction in period 1 was driven by local emission reduction. However, its reduction was not enough in period 2. The reduction of local emissions was negated by the increase of local activities and transported particulates, as well as the formation of secondary aerosol in Seoul from emissions transported from upwind regional sources. This resulted in PM₁₀ concentrations becoming stagnant in period 2. PM₁₀ reduction rate in the downwind area was faster than that in the upwind area. For the first 5 years, the reduction rate in the downwind area was great. Between all the stations observed, nearly all of the concentration difference was a result of more reduction in secondary aerosol. After 2005, coarse particles and primary elemental carbon (EC) played a key role in reducing the PM₁₀ concentration. Our findings on these two data features, and their causes, will help people to understand the most recent characteristics of particulate matters, in turn helping to update the control strategy for the continued improvement of particulate air quality in Seoul.     

Explaining the high PM<Subscript>10</Subscript> concentrations observed in Polish urban areas

The main goal of this paper is to identify the drivers responsible for the high particulate matter concentrations observed in recent years in several urban areas in Poland. The problem was investigated using air quality and meteorological data from routine monitoring network, air mass back trajectories and multivariate statistical modelling. Air pollution in central and southern part of the country was analysed and compared with this in northern-eastern “The Green Lungs of Poland” region. The analysis showed that in all investigated locations, there is a clear annual cycle of observed concentrations, closely following temperature-heating cycles, with the highest concentrations noted in January. However, the main drivers differ along the country, being either connected with regional background pollution (in the central part of the country) or with local emission sources (in the southern part). The occurrence of high PM₁₀ concentrations is most commonly associated with the influence of high-pressure systems that brought extremely cold and stable air masses form East or South of Europe. During analysed episodes, industrial point sources had the biggest (up to 70–80 %) share in PM₁₀ levels on the days with maximum PM pollution, while remote and residential/traffic sources determined the air quality in the early stages of the episodes. Principal component analysis (PCA) shows that secondary inorganic aerosols account for long-range transported pollution, As, Cd, Pb and Zn for industrial point sources, while Cr and Cu for residential and traffic sources of PM₁₀, respectively.     

Acidic Anions in PM<Subscript>10</Subscript> Particle Fraction in Zagreb Air,Croatia

This paper presents the results of 7 years continuous measurement of acidic anions chlorides, nitrates, and sulphates in PM₁₀ particle fraction in the city of Zagreb, Croatia. The mean annual mass concentrations of the investigated anions in PM₁₀ particle fraction varied from 0.28 to 0.95 μg/m³ for chlorides, from 3.21 to 7.87 μg/m³ for nitrates and from 3.98 to 9.71 μg/m³ for sulphates. The concentration levels of all measured anions showed significant seasonal differences. The most contributing to the PM₁₀ mass were sulphates, then nitrates, and then chlorides. The mobile source emission was an important contributor to particle mass.     

Day-night variability of PM<Subscript>10</Subscript> components at a Mediterranean urban site during winter

Daytime and nighttime PM₁₀ samples were collected during winter at an urban site in Southeastern Spain. Samples were subsequently analyzed to determine the concentrations of water-soluble ions, carbonaceous species, and metals. PM₁₀ daytime and nighttime concentrations were 26.1 and 20.6 μg/m³, respectively. This difference may be mainly attributed to the reduction in the number of vehicles during nighttime. Traffic-related components such as EC, Ca and other crustal elements, Cu or Zn, showed statistically significantly higher concentrations during daytime, suggesting that traffic emissions were more relevant than day-to-night differences in meteorological conditions. In contrast, no significant differences between daytime and nighttime levels of secondary inorganic ions (SO₄^2?, NO₃^? and NH₄⁺) were found. Primary and secondary organic carbon concentrations were estimated using the EC tracer method. As expected, POC levels were greater during the day due to increased vehicle exhaust emissions; conversely, higher SOC concentrations were registered during the nighttime period. This was most likely the result of a significant contribution of nighttime chemistry to the formation of secondary organic aerosols.     

Sources of trace metals in PM<Subscript>10</Subscript> from a petrochemical industrial complex in Northern Mexico

Concentrations, sources, and relative contributions of Cd, Cr, Cu, Fe, Mn, Pb, Ni, Ti, V, and Zn observed in PM₁₀ in the petrochemical industrial zone of Altamira in Northern Mexico are reported for the first time. Results show that oil refining, alloys, fertilizer, mining, metallurgical processes, and steel production industries are important contributions to PM₁₀ and metal concentrations. PM₁₀ concentrations ranged from 21 to 92 μg m^?3 and exceeded the revised 24-h average Mexican standard NOM-025-SSA1-2014 of 75 μg m^?3 12 % of the study period. The highest metal concentrations were Fe (1.64 μg m^?3), Mn (0.57 μg m^?3), and Ti (0.29 μg m^?3) and were associated with two dominant wind directions. Ti and Fe were associated with NNW winds (natural sources), and Mn and Fe were associated with SSW winds (ferromanganese industry). An average V/Ni ratio of 8.5 was found in this study with highest ratios associated to two dominant wind directions, NNW-NW and SE-SSE, suggesting origins from a fuel oil thermoelectric power plant and a refinery fuel oil, respectively. Pb was associated with industrial activity and never exceeded the Mexican standard of 1.5 μg m^?3 in 24 h. Zn and Cd were correlated with a dominant easterly wind, suggesting the presence of vehicle exhaust pollutants. The study of the size and shape of PM₁₀ particles by scanning electronic microscopy and energy-dispersive spectroscopy (SEM-EDS) allowed us to confirm the presence of trace metals associated to natural soils and clays, combustion, and industrial processes. The results presented here constitute the first efforts to evaluate toxic metals in a heavily industrialized area in Mexico and can be used to develop air quality management programs.     

Characteristics,Sources and Health Risk Assessment of Trace Metals in PM<Subscript>10</Subscript> in Panzhihua,China

Ambient PM₁₀ air samples were collected at two industrial sites and one urban residential site in the mining city of Panzhihua, China, from April, 2014, to January, 2015. Mass concentrations of ten trace metals (As, Cd, Cr, Ni, Co, V, Mn, Cu, Pb, and Zn) in PM₁₀ were determined by inductively coupled plasma-mass spectrometry. The results showed Zn, Pb, Cu, Mn and V were the most abundant elements from the industrial sites. Concentrations for Cd, Cr, Co, Ni, Mn and Cu at industrial sites greatly exceeded the air quality standards of the World Health Organization and the Chinese Ministry of Environmental Protection. Principal component analysis indicated that the main sources of the trace metals were steel smelting, fuel combustion, geological and mineral dust. Four different clusters of particles (i.e., mineral, calcium-containing, soot and aluminosilicate) were identified by scanning electron microscopy coupled with energy dispersive X-ray spectrometry. Chromium (Cr) was found to present the highest excess cancer risk, implying the potential for carcinogenic health effects in local inhabitants. Manganese (Mn) presented a non-carcinogenic health risk to children and adults, while the other metals were within acceptable limits.     

Elemental Contribution to the Mass of PM<Subscript>2.5</Subscript> in Guadalajara City,Mexico

The seasonal behavior of the mass of PM_2.5 and its elemental components and their contribution to the mass of the particles is described for two different sites in Guadalajara City. The average mass of the particles for the entire study period at the two sites, Centro and Miravalle (1.3 and 1.8 mg, respectively), showed significant differences (p < 0.05), while differences (p < 0.05) between seasons (rainy and dry season) only occurred at Miravalle. The total elemental contribution to the mass of the particles was 1.97% in Miravalle and 2.05% at Centro, with Iron and Titanium the largest contributors and most abundant elements for both sites. Likewise, the monthly contribution per element with respect to the monthly mass of all elements was estimated. The results revealed that the elements that present the biggest contribution to this mass were Iron, Titanium, Zinc and Magnesium. Iron was the largest contributor at both sites. At Miravalle, the contribution oscillated between 56 and 58% from January to June, while at Centro it oscillated between 55 and 40% for the same period of time.     

Atmospheric PM<Subscript>2.5</Subscript> Mercury in the Metropolitan Area of Mexico City

In this study, atmospheric mercury concentration in airborne particulate matter with an aerodynamic diameter ≤?2.5 µm (PM_2.5) was analyzed by ICP-MS. Samples were collected in the Mexico City Metropolitan Area (MCMA), during 2013, in five locations, Northwest, Northeast (NE), Central, Southwest and Southeast, along three seasons: dry warm, rainy, and dry cold (DC). It can be observed that NE shows the highest mercury concentration (p?<?0.05), where pollution events were identified. The seasonal distribution shows that samples collected during DC present the highest concentration (p?<?0.05). These results are in agreement with the distribution of important mercury industrial sources located in the northern urban area as well with the temperature and wind conditions during 2013. The comparison of data obtained in this work with those of similar previous studies clearly indicates a decrease, between 2006 and 2013, of mercury content in PM_2.5 collected in MCMA.     

Monitoring of long-term personal exposure to fine particulate matter (PM<Subscript>2.5</Subscript>)

Personal monitoring is of a demanding nature; thus, it is very difficult to obtain personal data for periods longer than a few days or a maximum of a few weeks. To fill this gap, we have performed a study in which personal exposure to particulate matter of aerodynamic diameter under 2.5 μm (PM_2.5) was monitored for almost 1 year. One healthy, adult, non-smoking, female student living in Prague (Czech Republic) was involved in the study. A battery-operated, fast-responding nephelometer was worn by the individual for a period of 10 months, recording PM_2.5 concentration every 5 min. A written time activity diary was used to record the experimental person's movement and the microenvironments visited. The dataset was divided into 12 different (seven indoor and four outdoor and transit) microenvironments. The overall average of the year-long measurement was 14.9 ± 52.5 μg.m⁻³ (median, 8.0 μg.m⁻³). The highest PM_2.5 average concentration was detected in restaurant microenvironments (294.4 μg.m⁻³), while the second highest concentration was recorded in an indoor microenvironment heated by wood and coal stoves (112.2 μg.m⁻³). The lowest mean aerosol concentrations were detected outdoors in a rural/natural environment (7.0 μg.m⁻³) and indoors at the monitored person's home (9.3 μg.m⁻³). During the measurement period, isolated and brief, but very high concentration excursions over 500 μg.m⁻³ or even over 1,000 μg.m⁻³ were recorded. However, they accounted for less than 0.5% of the total time of personal exposure. We conclude that continuous long-term monitoring is a good tool capable of disclosing the frequency and severity of short-term peak events of high particulate concentrations, which may be associated with adverse health effects.     

PM<Subscript>2.5</Subscript> and Associated Polycyclic Aromatic Hydrocarbon and Mutagenicity Emissions from Motorcycles

In this study, PM(2.5) in diluted exhausts of motorcycles are collected and emission characteristics of PM(2.5)-associated polycyclic aromatic hydrocarbons (PAHs) and mutagenicities are investigated. The measured mutagenicity emission factors with metabolic activation for new fuel injection, used fuel injection, new carburetor and used carburetor motorcycles are 7.77 x 10(4), 1.18 x 10(5), 1.32 x 10(5) and 1.15 x 10(5) rev/km, respectively. The mutagenicity emission factors with metabolic activation are higher than the corresponding values without metabolic activation. The average PAH emission factors are 12.3, 16.3, 25.5 and 26.5 mug/km for new and used fuel-injection motorcycles, and new and used carburetor-operated motorcycles, respectively. The correlation coefficients between PAHs and mutagenicity emission factors are higher with metabolic activation (0.59) than that without metabolic activation (0.31).     

The PM<Subscript>10</Subscript> compositions,sources and health risks assessment in mechanically ventilated office buildings in an urban environment

Office buildings can be considered a “second home” for working people and so the contribution of pollutants in this indoor environment to a person’s overall exposure is significant. The aims of this study were to examine the composition of PM₁₀ and the sources influencing the indoor and outdoor office environments. The PM₁₀ sampling was performed using a mini-vol portable sampler at two sampling sites from May to August 2014 for daily 24 h sampling. The concentrations of ionic species (F^?, Cl^?, NO₃ ^?, SO₄ ^2?) were analysed using ion chromatography while the concentration of major elements (Mg, Ca, K, Na) and trace elements (Mn, Ni, Fe, Cu, Zn, Pb, Cr, Cd, Al) were determined by inductively couple plasma-mass spectrometry (ICP-MS). The concentration of NH₄ ⁺ was determined using the indophenol blue method. The results showed that the average concentrations of PM₁₀ were 61.3?±?27.0 μg/m³ (indoor) and 101?±?42.8 μg/m³ (outdoor) with an indoor/outdoor ratio value of <1. The dominant components in PM₁₀ for both the indoor and outdoor environments were NO₃ ^?, SO₄ ^2?, Na, Fe, Al and Zn. Source apportionment analysis of the PM₁₀ composition identified three sources of PM₁₀ in the indoor and outdoor environments. The major source for indoor PM₁₀ was Earth’s crust elements (95 %) followed by oil burning and human activities (4 %) and motor vehicles (1 %). The major source for outdoor PM₁₀ was the Earth’s crust and motor exhaust emissions (80 %) with contributions of other sources such as oil burning and human activities (18 %) and motor vehicles (2 %). The potential health risks for trace elements in PM₁₀, via inhalation exposure to the indoor occupants, show that the total hazard quotient (HQ) value was slightly higher than acceptable limits (1.0). The total excess life time carcinogenic risk (ELCR) value for both sampling stations was higher than the acceptable limit (1.0?×?E?6), suggesting a high exposure to carcinogenic risk. This study suggests there is a high contribution of outdoor sources to the indoor office environment where PM₁₀ can significantly affect the indoor air quality and occupant health.