Radicals in the church

Polycyclic aromatic hydrocarbons and trace metals in mosque's carpet dust of Riyadh, Saudi Arabia, and their health risk implications

The main objectives of this work were to identify and determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) and trace metals in carpet dust samples from various mosques of the city of Riyadh and to assess the health risks associated with the exposure to these pollutants. Therefore, 31 samples of mosque's carpet dust from Riyadh were collected. The results showed that 14 PAHs were present in the dust samples with concentrations ranged from 90 to 22,146 ng g^-1 (mean = 4096 ± 4277 ng g^-1) where low molecular weight compounds were dominant. The presence of PAHs were in the order of naphthalene > chrysene and benzo(b)fluoranthene > benzo(a)pyrene > acenaphthene and benzo(k)fluoranthene > pyrene and the absence of indeno(1,2,3-cd)pyrene and dibenz(a,h)anthracene. The diagnostic ratio coupled with principle component analysis (PCA) revealed mix sources of petrogenic from traffic, stack emission, and pyrogenic inputs from essence and perfumed wood burning. Trace metals were significant in the dust samples, and their concentrations decrease in the order of Zn, Mn, Cu, Cr, Pb, Ni, and V where Zn being the highest (94.4 ± 91.5 μg g^-1) and indium was the lowest (1.9 ± 9.3 μg g^-1). The trace metals were major in southern and central parts of Riyadh and followed the order of central Riyadh > southern Riyadh > western Riyadh > eastern Riyadh > northern Riyadh. Estimated risk based on the total PAHs was found to be 4.30 × 10^-11 for adult and 1.56 × 10^-11 for children. Elemental non-cancer risk for adults ranged from 7.9 × 10^-4 for Co to 7.58 × 10^-1 for Li and for children ranged from 3.70 × 10^-3 for Co to 3.54 for Li. Policy implication and mitigations of PAHs in Riyadh and Saudi Arabia were highlighted.

Particle exposure in a baroque church during Sunday Masses

Particle concentrations were measured in a Baroque church during five Sunday Masses. The highest particle number and mass concentrations were observed when both candles and the incense were burned. They were respectively 16.8 and 14.3 times higher than outdoors for submicron particles. The exposure to particles experienced by the churchgoers, especially priests and church workers who participated in several Masses on that day, was considerably higher than the exposure experienced at the same time outdoors.

Potential effects of particulate matter from combustion during services on human health and on works of art in medieval churches in Cyprus

Indoor and outdoor particulate matter (PM0.3-10) number concentrations were established in two medieval churches in Cyprus. In both churches incense was burnt occasionally during Mass. The highest indoor PM0.5-1 concentrations compared with outdoors (10.7 times higher) were observed in the church that burning of candles indoors was allowed. Peak indoor black carbon concentration was 6.8 microg m(-3) in the instances that incense was burning and 13.4 microg m(-3) in the instances that the candles were burning (outdoor levels ranged between 0.6 and 1.3 microg m(-3)). From the water soluble inorganic components determined in PM10, calcium prevailed in all samples indoors or outdoors, whilst high potassium concentration indoors were a clear marker of combustion. Indoor sources of PM were clearly identified and their emission strengths were estimated via modeling of the results. Indoor estimated PM0.3-10 mass concentrations exceeded air quality standards for human health protection and for the preservation of works of art.

Role of oxidative damage in toxicity of particulates

Particulates are small particles of solid or liquid suspended in liquid or air. In vitro studies show that particles generate reactive oxygen species, deplete endogenous antioxidants, alter mitochondrial function and produce oxidative damage to lipids and DNA. Surface area, reactivity and chemical composition play important roles in the oxidative potential of particulates. Studies in animal models indicate that particles from combustion processes (generated by combustion of wood or diesel oil), silicate, titanium dioxide and nanoparticles (C60 fullerenes and carbon nanotubes) produce elevated levels of lipid peroxidation products and oxidatively damaged DNA. Biomonitoring studies in humans have shown associations between exposure to air pollution and wood smoke particulates and oxidative damage to DNA, deoxynucleotides and lipids measured in leukocytes, plasma, urine and/or exhaled breath. The results indicate that oxidative stress and elevated levels of oxidatively altered biomolecules are important intermediate endpoints that may be useful markers in hazard characterization of particulates.

Symptoms prevalence among office workers of a sealed versus a non-sealed building: associations to indoor air quality

OBJECTIVES

An increasing number of complaints related to time spent in artificially ventilated buildings have been progressively reported and attributed, at least in part, to physical and chemical exposures in the office environment. The objective of this research was to investigate the association between the prevalence of work-related symptoms and the indoor air quality, comparing a sealed office building with a naturally ventilated one, considering, specially, the indoor concentration of TPM, TVOCs and the main individual VOCs.

METHODS

A cross-sectional study was performed to compare the prevalence of sick building syndrome (SBS) symptoms among 1736 office workers of a sealed office building and 950 of a non-sealed one, both in Rio de Janeiro's downtown. The prevalence of symptoms was obtained by a SBS standardized questionnaire. The IAQ of the buildings was evaluated through specific methods, to determine the temperature, humidity, particulate matter and volatile organic compound (VOC) concentrations.

RESULTS

Upper airways and ophthalmic symptoms, tiredness and headache were highly prevalent in both buildings. Some symptoms were more prevalent in the sealed building: "eye dryness" 33.3% and 27.1% (p: 0.01); "runny nose" 37.3% and 31.3% (p: 0.03); "dry throat" 42% and 36% (p: 0.02); and "lethargy" 58.5% and 50.5% (p: 0.03) respectively. However, relative humidity and indoor total particulate matter (TPM) concentration as well as total volatile organic compounds (TVOCs) were paradoxically greater in the non-sealed building, in which aromatic compounds had higher concentration, especially benzene. The analysis between measured exposure levels and resulting symptoms showed no association among its prevalence and TPM, TVOCs, benzene or toluene concentration in none of the buildings.

CONCLUSIONS

Other disregarded factors, like undetected VOCs, mites, molds and endotoxin concentrations, may be associated to the greater prevalence of symptoms in the sealed building.

Organic compounds in office environments - sensory irritation, odor, measurements and the role of reactive chemistry

Abstract Sensory irritation and odor effects of organic compounds in indoor environments are reviewed. It is proposed to subdivide volatile organic compounds (VOCs) into four categories: (i) chemically non-reactive, (ii) chemically 'reactive', (iii) biologically reactive (i.e. form chemical bonds to receptor sites in mucous membranes) and (iv) toxic compounds. Chemically non-reactive VOCs are considered non-irritants at typical indoor air levels. However, compounds with low odor thresholds contribute to the overall perception of the indoor air quality. Reported sensory irritation may be the result of odor annoyance. It appears that odor thresholds for many VOCs probably are considerably lower than previously reported. This explains why many building materials persistently are perceived as odorous, although the concentrations of the detected organic compounds are close to or below their reported odor thresholds. Ozone reacts with certain alkenes to form a gas and aerosol phase of oxidation products, some of which are sensory irritants. However, all of the sensory irritating species have not yet been identified and whether the secondary aerosols (ultrafine and fine particles) contribute to sensory irritation requires investigation. Low relative humidity may exacerbate the sensory irritation impact. Practical Implications Certain odors, in addition to odor annoyance, may result in psychological effects and distraction from work. Some building materials continually cause perceivable odors, because the odor thresholds of the emitted compounds are low. Some oxidation products of alkenes (e.g. terpenes) may contribute to eye and airway symptoms under certain conditions and low relative humidity.