No abstract

Particulate matter originates from a variety of sources in Makkah, Saudi Arabia. Since Makkah is situated in an arid region and is a very busy city due to its religious importance in the Muslim world, PM 10 concentrations here exceed the international and national air quality standards set for the protection of human health. The main aim of this paper is to model PM 10 concentrations with the aid of meteorological variables (wind speed, wind direction, temperature, and relative humidity) and traffic related air pollutant concentrations (carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO 2 ), sulphur dioxide (SO 2 ) and lag_PM 10 concentrations), which are measured at the same location near Al-Haram (the Holy Mosque) in Makkah. A Generalized Additive Model was developed for predicting hourly PM 10 concentrations. Predicted and observed PM 10 concentrations are compared, and several metrics, including the coefficients of determination (R 2 = 0.52), Root Mean Square Error (RMSE = 84), Fractional Bias (FB = -0.22) and Factor of 2 (FAC2 = 0.88), are calculated to assess the performance of the model. The results of these, along with a graphical comparison of the predicted and observed concentrations, show that model is able to perform well. While effects of all the covariates were significant (p-value < 0.01), the meteorological variables, such as temperature and wind speed, seem to be the major controlling factors with regard to PM 10 concentrations. Traffic related air pollutants showed a weak association with PM 10 concentrations, suggesting road traffic is not the major source of these. No modeling study has been published with regards to air pollution in Makkah and thus this is the first work of this kind. Further work is required to characterize road traffic flow, speed and composition and quantify the contribution of each source, which is part of the ongoing project for managing the air quality in Makkah.

Environmental Study in Subway Metro Stations in Cairo, Egypt: Abdel Hameed A. Awad, Air Pollution Department, National Research Centre—Airborne viable and non‐viable measurements were carried out in two different metro stations, one located in a tunnel and the other on the surface. The concentrations of airborne total viable bacteria (incubated at 37°C and 22°C), staphylococci, suspended dust and oxidants (ozone) were higher in the air of the tunnel station than those recorded at the surface station. In contrast, spore forming bacteria, Candida spp, fungi and actinomycetes were found at slightly higher levels in the surface station than in the tunnel station. A statistically significant difference (p<0.01) was found between the levels of suspended dust at both stations. Cladosporium, Penicillium and Aspergillus species were the dominant fungi isolates. Fusarium, Aspergillus and Penicillium are the most common fungi that produce toxins. Under certain circumstances (host susceptibility, infective dose and aerodynamic diameter) some of the airborne microorganisms e.g. actinomycetes and Aspergillus species and staphylococci may cause health problems in exposed persons based on toxic or allergic reactions.

Airborne fungal counts and types were examined in three selected regions in Egypt. Two of the sampling sites are rural areas, one cultivated with chamomile and the second with vegetable. The third site is located in an urban area. A sedimentation method was used to isolate airborne fungal spores. Airborne fungal spore counts averaged 71 AE 19, 64 AE 14 and 175 AE 79 cfu/p/h in the urban, vegetable and chamomile growing areas, respectively. A total of 1486 fungal colonies belonging to 32 genera were identified. Alternaria (7.5-59.9%), Aspergillus (11.2-38.9%), Penicillium (9.5-15%) and Cladosporium (7.78-17.5%) were the predominant fungal genera found in all sampling sites. Alternaria (42-59.9%) and Aspergillus (38.9%) were the common fungal genera in the cultivated and urban areas, respectively. Vegetation is considered the main source of Alternaria, whereas Aspergillus, Penicillium and Cladosporium are related to local microenvironments and urbanization.

Objective: The present work aimed to investigate the relationship between occupational exposure to airborne molds, serum aflatoxin B1 (AFB1), and liver enzymes of workers handling wheat flour. Methods: The study included 90 bakers, 100 flour milling workers, and 100 controls with no exposure to flour dust. Workplace aspects such as temperature and relative humidity were measured. Airborne fungi were collected and identified. In all subjects included, the serum levels of AFB1, serum albumin (Alb), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were measured. Results: Air temperature and relative humidity were found to be higher in bakeries than in flour mill sections. Airborne Aspergillus species were isolated in dust particles <8 µm in size. The concentration of Aspergillus flavus and Aspergillus niger were higher in bakeries than in the flour mill sections. They were higher in the grinding section than in other mill sections. The serum AFB1-Alb adduct and ALP levels were significantly higher in bakers compared to milling workers ( p < 0.0001, p = 0.05), respectively. The liver enzymes AST and ALT were significantly higher among milling workers and bakers than controls ( p < 0.05, p < 0.0001), respectively. The duration of exposure was significantly correlated with serum AFB1 in bakers. Moreover, there was significant correlation between serum AFB1, each of ALT and AST levels in bakers. Conclusions: chronic occupational exposure to high concentrations of Aspergillus in workplaces may cause elevations in serum levels of AFB1 and liver enzymes in workers exposed to flour dust. Hence, worker protection measures should be consistently adopted and enforced at the workplace.