Human exposure to hydrogen sulphide concentrations near wastewater treatment plants

The hydrogen sulphide (H2S) levels from wastewater treatment plants (WWTPs) in Curitiba, Brazil have been quantified for the first time. H2S generated by anaerobic decomposition of organic matter in WWTPs is a cause for concern because it is an air pollutant, which can cause eye and respiratory irritation, headaches, and nausea. Considering the requirement for WWTPs in all communities, it is necessary to assess the concentrations and effects of gases such as H2S on populations living and/or working near WWTPs. The primary objective of this study was to evaluate the indoor and outdoor concentration of H2S in the neighbourhood of two WWTPs located in Curitiba, as well as its human health impacts. Between August 2013 and March 2014 eight sampling campaigns were performed using passive samplers and the analyses were carried out by spectrophotometry, presenting mean concentrations ranging from 0.14 to 32 μg m− 3. Eleven points at WWTP-A reported H2S average concentrations above the WHO recommendation of 10 μg m− 3, and 15 points above the US EPA guideline of 2 μg m− 3. At WWTP-B the H2S concentration was above US EPA guideline at all the sampling points. The I/O ratio on the different sampling sites showed accumulation of indoor H2S in some instances and result in exacerbating the exposure of the residents. The highest H2S concentrations were recorded during the summer in houses located closest to the sewage treatment stations, and towards the main wind direction, showing the importance of these factors when planning a WWTP. Lifetime risk assessments of hydrogen sulphide exposure showed a significant non-carcinogenic adverse health risk for local residents and workers, especially those close to anaerobic WWTPs. The data indicated that WWTPs operated under these conditions should be recognized as a significant air pollution source, putting local populations at risk

Passive dosimetry as an alternative technique to dynamic enrichment of organic pollutants of indoor air

Evaluation of the quality of indoor air was carried out in 20 apartments, 3 offices, and 3 laboratories in the Tricity area in Poland with reference to concentrations of selected volatile organic compounds (VOCs), such as benzene, toluene, butyl acetate, ethylbenzene, m-xylene, styrene, and m-dichlorobenzene. The time dependence of concentrations of selected VOCs in a newly erected building was studied. Two different techniques were used for the isolation and preconcentration of analytes from air samples: a passive method employing a home-made permeation-type passive sampler and a dynamic method based on a sorption tube. In both cases, activated charcoal was used as a sorption medium (trap packing). The sorption tube was used to validate the results obtained by the passive method, as well. In the majority of dwellings examined, the concentrations of air pollutants were relatively low and did not exceed the MAC values. No significant differences were observed between MAC concentrations determined by using the passive or the dynamic method of air sampling. The results obtained by both sampling methods were characterized by similar precision

FROM HARVESTING TO DISTILLATION – EFFECT OF ANALYTICAL PROCEDURES ON THE YIELD AND CHEMICAL COMPOSITION OF RHODODENDRON TOMENTOSUM (LEDUM PALUSTRE) ESSENTIAL OIL

Abstract: Rhododendron tomentosum possesses the anti-inflammatory, analgesic and antimicrobial properties, determined by the chemical composition of its essential oil. The effects of place (Miszewko, Lubichowo) and time of harvesting (June, November) as well as drying (air-drying, oven-drying, freeze-drying) and isolation (in Deryng, Clevenger and Likens-Nickerson apparatus) procedures on the yield and quality of R. tomentosum essential oil were studied. Ledol (8.1-14.4%), palustrol (6.9-13.0%) and γ-terpineol (8.5-9.1%) predominated in the plants collected from Miszewko, while γ-terpineol (11.8-22.2%), p-cymene (5.3-12.6%) and geranyl acetate (5.7-7.5%) prevailed in the biomass from Lubichowo. The shoots produced more volatiles in the flowering phase than in the end of the vegetation. Oven-drying at 30ºC with controlled air flow was suggested as the quick dehydration method. Hydrodistillation in Deryng and Clevenger apparatus resulted in comparatively high essential oil yield (about 1%). All studied drying and distillation methods did not influence significantly the general profile of R. tomentosum essential oil

Evaluation of indoor air quality on the basis of measurements of VOC concentrations

Measurement of concentrations levels of volatile organic compounds (VOC) such as benzene, toluene, butyl acetate, ethylbenzene, m-xylene, styrene and m-dichlorobenzene was carried out in three newly erected and remodelled dwellings in Tricity area. To collect the series of air samples the active and passive methods were used. In both cases activated charcoal was applied as a sorption medium. The samples were liberated by solvent extraction, and analyzed by capillary column gas chromatography, employing a flame ionisation detector. The study also attempted to examine the time dependence of concentrations of selected VOC in each investigated dwelling. This was accomplished by at least triplicate measurements of the IAQ. The experimental results showed that values for analyzed VOC were exceeded (even a few orders of magnitude) for the measurements made before inhabiting of the occupants, in every investigated dwelling. The concentrations of the investigated VOC decreased significantly with time, which should be expected, although in some cases the levels of selected VOC remained still high. Our experience indicates that application of two different indoor air sampling techniques to determine analytes of interest, though more laborious and time consuming, can lead to significant conclusions concerning indoor air quality

Application of Passive Samplers in Monitoring of Organic Constituents of Air

The principles of passive dosimetry, which has been known for over 100 years, are finding an ever increasing use in analytical practice and are being used as a convenient technique for isolation and enrichment of analytes from various environmental media. Due to its simplicity, a variety of designs, as well as the possibility of using a number of different final determination techniques, passive dosimetry has been applied in the analysis of organic and inorganic air pollutants, both in the outdoor and the indoor and workplace atmospheres, as well as in the monitoring of water and soil pollution. This paper is an attempt to review the designs of existing passive samplers, the media used to trap analytes and the techniques used for the release of the trapped analytes and their final determination

In vitro propagation of Rhododendron tomentosum - an endangered essential oil bearing plant from peatland

Rhododendron tomentosum Harmaja (formerly Ledum palustre L.) is a medicinal peat bog plant native to northern Europe, Asia and North America. This plant has a distinctive aroma thanks to the presence of essential oil, to which it also owes its anti-inflammatory, analgesic, antimicrobial and insecticidal properties. However, in Europe R. tomentosum is classified as an endangered species, mainly due to degradation of peatlands. In the present work, the micropropagation protocol for R. tomentosum was established for the first time, providing both an ex situ conservation tool and a means of continuous production of in vivo and in vitro plant material for further studies. R. tomentosum microshoots were initiated from leaf explants and further multiplied using Schenk- Hildebrandt (SH) medium supplemented with 9.84 μM 2iP and 1.00 μM TDZ. The shoots were elongated on the SH medium supplemented with 24.6 μM 2iP and subsequently rooted using the perlite substrate saturated with half-strength Woody Plant medium supplemented with 1.0% sucrose and 4.92 μM IBA. The regenerated plants were hardened on the phytohormone-free SH medium and acclimatized using 3:1:1 deacidified peat:perlite:gravel substrate. The identity of the mother plant was confirmed at morphological and molecular levels and Random Amplified Polymorphic DNA (RAPD) method was implemented to assess the genetic fidelity of the regenerants. The essential oil content of the maternal plant, in vitro shoots and the regenerants was determined by steamdistillation, and the obtained volatile fractions were analyzed by GC/MS