Indoor and outdoor elemental mercury: a comparison of three different cases.

Gaseous elemental mercury (GEM) concentrations were determined in three different indoor environments: an office in a building with no indoor sources of mercury (Bldg. I), an office affected by indoor mercury emissions from an adjacent laboratory (Bldg. II), and finally, an office where an outdoor mercury spill occurred accidentally (Bldg. III). The maximum recorded indoor GEM concentrations, with the largest variation in time, were observed in Bldg. II, with a continuous indoor mercury source (lower to upper quartile 15 to 62 ng m-3). The lowest values were recorded in Bldg. I (lower to upper quartile 3 to 5 ng m-3), where indoor GEM levels were affected mainly by the exhaust of vehicles in the parking lot of the building. The monitoring of GEM indoors (lower to upper quartile 15 to 42 ng m-3), and outdoors (in several heights) of the Bldg. III, revealed that the cleaning up procedure that followed the spill was not adequate. Auxiliary measurements in the first two cases were the indoor microclimatic conditions, as well as the indoor CO2 concentrations, and in the third case the outdoor meteorological data. The exhaust of vehicles, the chemical reagents, and an outdoor mercury spill were found to mainly affect the observed indoor GEM levels. People in Bldg. II and people walking through the area, where Hg0 was spilled, were found to be exposed to concentrations above some guide values.

Case study. Health hazards of automotive repair mechanics: thermal and lighting comfort, particulate matter and noise.

An indoor environmental quality survey was conducted in a small private automotive repair shop during May 2009 (hot season) and February 2010 (cold season). It was established that the detached building, which is naturally ventilated and lit, had all the advantages of the temperate local climate. It provided a satisfactory microclimatic working environment, concerning the thermal and the lighting comfort, without excessive energy consumption for air-conditioning or lighting. Indoor number concentrations of particulate matter (PM) were monitored during both seasons. Their size distributions were strongly affected by the indoor activities and the air exchange rate of the building. During working hours, the average indoor/outdoor (I/O) number concentration ratio was 31 for PM0.3-1 in the hot season and 69 for the cold season. However I/O PM1-10 number concentration ratios were similar, 33 and 32 respectively, between the two seasons. The estimated indoor mass concentration of PM10 for the two seasons was on average 0.68 mg m(-3) and 1.19 mg m(-3), i.e., 22 and 36 times higher than outdoors, during the hot and the cold seasons, respectively. This is indicative that indoor air pollution may adversely affect mechanics' health. Noise levels were highly variable and the average LEX, 8 h of 69.3 dB(A) was below the European Union exposure limit value 87db (A). Noise originated from the use of manual hammers, the revving up of engines, and the closing of car doors or hoods. Octave band analysis indicated that the prevailing noise frequencies were in the area of the maximum ear sensitivity.

Mapping the noise in a Greek general hospital.

Sound pressure levels were monitored in a general hospital, in Greece, at ten indoor locations and at three outdoor locations, in the yard of the building. The selected indoor locations are representative of distinct activities that are common in every hospital, such as the emergency department, patient wards and several supporting services, like washing the clothes or the dishes. Noise levels were highly variable in each monitoring location and depended on the activities in the room, such as conversations, medical equipment in use, analytical devices or other machinery in operation. The highest noise levels that were recorded were in the blood donation unit and in the laundry room (the L10,8h was 73 and 79 dB(A) respectively), mainly due to the opening/closing of the metal lids of garbage bins in the first location and due to the wringing of the clothes in the second. Indoor background noise levels i.e. the L95,8h values, were more than 55 dB(A) and higher than the respective outdoor values (except of the L95,8h in one ward of the paediatric ward). The calculated average LEX, 8h was 69.3 dB(A), below the European Union lower exposure action limit value, i.e. 87 dB(A), that was set to prevent hearing loss of the employees. However, noise levels in the wards, in the emergency and the outpatient department were above the values suggested by international guidelines for a healing environment. Sound spectra revealed peaks in frequencies that were representative of the sources of the noise and also the presence of low frequency noise components.

Characterisation of indoor airborne particles by using real-time aerosol mass spectrometry.

An Aerosol Time-of-Flight Mass Spectrometer (ATOFMS; TSI 3800) was deployed to Athens (Greece) during August 2003. The instrument provides information on a polydisperse aerosol, acquiring precise aerodynamic diameter (+/-1%) within the range 0.3 to 3 mum and individual particle positive and negative mass spectral data in real time. Sampling was carried out indoors and outdoors at an office in a building on a minor road in the city centre and various outdoor and indoor sources were identified. Specific outdoor particles such as dust and carbon particles were detected in indoor air. The generation of particles from indoor sources was studied and several different types of particle were found to be present in environmental tobacco smoke (ETS): three were potassium-rich (with differing proportions of carbon) emitted directly in the exhaled mainstream smoke. Two other types arose mainly when the cigarette was left smouldering on an ash-tray. Another particle type exhibited a strong signal at m/z 84, most likely due to a nicotine fragment. The temporal trend of this specific particle type showed likely condensation of semi-volatile constituents on existing potassium-rich particles. A release of insect repellent in the room was also successfully monitored.

Energy flux parametrization as an opportunity to get Urban Heat Island insights: The case of Athens, Greece (Thermopolis 2009 Campaign).

Energy flux parameterization was effected for the city of Athens, Greece, by utilizing two approaches, the Local-Scale Urban Meteorological Parameterization Scheme (LUMPS) and the Bulk Approach (BA). In situ acquired data are used to validate the algorithms of these schemes and derive coefficients applicable to the study area. Model results from these corrected algorithms are compared with literature results for coefficients applicable to other cities and their varying construction materials. Asphalt and concrete surfaces, canyons and anthropogenic heat releases were found to be the key characteristics of the city center that sustain the elevated surface and air temperatures, under hot, sunny and dry weather, during the Mediterranean summer. A relationship between storage heat flux plus anthropogenic energy flux and temperatures (surface and lower atmosphere) is presented, that results in understanding of the interplay between temperatures, anthropogenic energy releases and the city characteristics under the Urban Heat Island conditions.