Coarse particles are primarily deposited via sedimentation, commonly referred as dust fall (DF). This study presented the monthly and spatial variations of atmospheric DF and their elemental components (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, Sr, Ti, V, Si, and Hg). Dust samples were collected from four urban and suburban sampling sites around Tabriz, Iran, by using the ASTM method D-1739 during April to September 2017. Moreover, the ICP-OES was used to determine metal components of the DF. The obtained results showed that the DF amount ranged between 1.8-27.6 (7.4 ± 5.6) g/m 2 .month. The elements of Fe (11863-13,906 mg/Kg and 85%-89%), Al (858-1205 mg/Kg and 4%-8%), and Si (274-386 mg/Kg) were the dominant elemental concentrations of the DF. The average value of enrichment factor (EF) for Hg, Pb, Cu, Sr, Co, Ni, Mn, and V was greater than 10 in all the samples, showing that anthropogenic sources emit a considerable amount of elements in DF rather than the soil or Urmia lake bed. The result of correlations between the concentration of dust fall with humidity, temperature, wind speed, and precipitation showed that there was a direct relationship between the amount of dust fall and wind speed while humidity, precipitation, and temperature were inversely proportional to the amount of dust fall. This study revealed that earth crust and anthropogenic activities such as vehicle traffic, combustion of fossil fuel, and different industrial activities were the main sources of the DF in the studied areas.

Article Info Background: This study aimed to measure the sound level and assess the association between noise annoyance and general health in Iranian nurses at Tabriz Pediatric Hospital in neonatal, infectious, internal, NICU, and emergency care wards. Materials and Methods: The noise level was measured continuously according to ISO9612. The general health questionnaire-28, the noise annoyance scale based on ISO15666, and demographic characteristics were the questionnaires used in this study. The study was conducted at Tabriz specialty and subspecialty Hospital for children, which includes different care wards and admits many patients to the hospital. Results: The highest 24-hour mean noise level (dBA) was measured in the emergency (69.65±1.68) ward. The highest mean noise level during the morning, afternoon, and night shifts belonged to the emergency ward at 69.53±0.27, 69.30±0.39, and 69.85±0.43, respectively. According to the results, the association between the equivalent sound exposure level and noise annoyance was significant. The highest mean score of the total GHQ (39.78 ±12.01) was obtained in the emergency ward, and the lowest mean score (30.20 ±7.15) was obtained in the neonatal ward. The rassociation between the total scale of GHQ-28 and GHQ-28 subscales was significantly positive in all wards. Conclusion: The mean of the LAeq (dBA), in different wards of the studied hospital, was higher than the levels suggested by the US-EPA, the WHO, the AAP, and the national standard. Accordingly, since the mentioned wards play a vital role in treatment procedures, effective management-technical noise reduction measures are required to be adopted in these wards.

No abstract