The objective of this experiment was to evaluate the effect of Chamaecyparis obtus extract to reduce odor emissions released from the swine feeding operations. Finisher pigs [Landrace × (Yorkshire × Duroc)] with an initial body weight averaging 50 kg were housed separately in two rooms with eighty eight pigs in each room at a swine feeding operation site. C. obtus extract was sprayed in the room by ceiling sprayer for one minute at twice per day during two months. Concentrations of odorous compounds from air in the room of the swine feeding operation were analyzed at four times during two months. Levels of butyric acid, valeric acid, i-butyric acid, ivaleric acid, skatole, methylmercaptan, and trimethylamine tended to decrease in C. obtus extract spray treatment group compared to the non-spray treatment group (P > 0.05). Odor activity values of butyric acid, valeric acid, skatole and trimethylamine were higher than other odorous compounds and decreased by 72%, 76%, 54% and 20%, respectively, in C. obtus extract spray treatment group compared to the non-spray group. Taken together, C. obtus extract showed an odor reducing capability in the air of a swine feeding operation suggesting that it possesses anti-bacterial properties as well as having a dust removal and masking effect.
The consumer products in the living environments include a variety of chemicals which could be harmful in the human health. The aim of this study was to assess the inhalation exposure and risk for cleaning workers who had used bleach in the university. A total of 81 cleaning workers took part in this study. Frequency and amount of cleaning bleach during working hours were investigated by questionnaire interviews. Exposure assessment was used by the exposure algorithm and exposure factors. Used cleaning bleaches were analyzed to identify the ingredients, and risk by exposure was assessed by separating as carcinogen and non-carcinogen substances. The results of chemical substances and the questionnaire were used to assess the exposure factors, and the inhalation doses were calculated through inhalation exposure algorithm. According to the questionnaires for the cleaning workers, frequence of cleaning bleach was 11.66 ± 7.21 times per month. And average usage time and amount per cleaning work were 30.78 ± 36.00 minute and 20099.53 ± 12998.60 mg, respectively. Risks for carcinogenic substances of formaldehyde, ethylbenzene, and chloroform were exceeded by 56.79%, 27.16%, and 82.72% as the reference value of 10−6, respectively.
This study compared the stability of odor compounds in three different types of polymer sampling bags. Tedlar, PET (polyethylene terephthalate) and aluminized polyester bag were used. A sample was collected from the interior of a new automobile which was parked in an outdoor parking lot. It was found that the Tedlar bag showed lower stability for odor active compounds than the PET bag. Meanwhile, the PET bag had good stability for odor compounds compared to the aluminized polyester bag. The PET bag showed a stability for the molecules smaller than toluene that was comparable to the canister, but showed a lower recovery for molecules bigger than C7. The FID signal of the sample in the PET bag was reduced by 1.7times after 3days storage compared to 24 h storage. The number of detected odor active compounds was reduced by half, and odor intensity was also decreased by 2~3 degrees. Considering the factors of repeated use, usability and price, a PET bag covered with a black plastic bag was the most appropriate approach for odor sampling in an automobile interior.
The objective of this study was to investigate ELF-MF exposure levels in infant living environmental spaces at daycare centers. To achieve the objective of the study, we surveyed ELF-MF levels using EMDEX II at daycare centers from October 2013 to October 2014. The ELF-MF level of 53 daycare centers in terms of arithmetic mean (AM) and geometric mean (GM) were 0.59 ± 0.76 mG and 0.33 mG, respectively. And the ELF-MF level of 260 daycare center classrooms was 0.50 ± 0.71 mG (GM: 0.28 mG). The exposure levels of ELF-MF for all daycare centers were far below the recommended standards cited in guidelines in Korea (833 mG) and international reference levels proposed by WHO or ICNIRP (2,000 mG). Furthermore, we discovered out that as distance increased, ELF-MF emission levels decreased significantly in all electrical instruments. Below the 2 mG ELF-MF levels when an electrical instrument moved away stage 1 (Grade). Thus, these results will provide useful data for the determination of ELF-MF management and reduction methods at infant daycare centers.
Per capita nail-products use and airborne VOCs emission in four techniques of nail care (full coat coloring, UVgel polish, repair silk, and acrylic overlay) are estimated in this study. These assessments were carried out in a sealed test chamber using artificial hand and nails. A polish remover and a gel cleanser as cleanser and acrylic liquid as solvent were the most commonly used nail products in all 4 of the nail care techniques. Acetone, isopropyl alcohol, and methanol, which are major components of a polish remover, were commonly detected in all nail care techniques while acetone was detected the most. In addition to these airborne VOCs, a variety of other components such as ethyl acetate, cyclohexane, and toluene were identified in full coat coloring technique. In the process of UV-gel polish care technique, the main airborne VOCs were caused by solvents and were not involved in the curing process of UV gels (base gel and top gel) and gel bonder. In the case of repair silk nail care techniques, which generated the most VOCs, the total amount of VOCs detected was about 1,118.8 ± 359.6 mg/capita. Of the VOCs, butane (862.2 ± 283.9 mg/capita), which is contained in glue dryer, represented the largest share. In the process of acrylic overlay nail care technique, ethyl methacrylate (EMA), which is the basic element of acrylic, and highly toxic methyl methacrylate (MMA) were detected at 396.6 ± 42.3 mg/capita and 141.8 ± 8.2 mg/capita, respectively. The per capita data is very useful in designing a ventilation system for environmental improvement of a nail shop and setting a health care policy for nail artists and customers.
It is known that air pollutants such as fine dust and exhaust gas from vehicles are harmful to human health. In particular, the black carbon emitted by vehicles is known to cause a large number of premature deaths. This study analyzed the effect of a noise barrier on the inflow amount of black carbon from a nearby high traffic road to a school area, using numerical analysis performed at two elementary schools. Also, the correlation between the noise barrier’s shape, height and the inflow amount of black carbon was assessed. As a result, it was found that the higher the noise barrier, the lower the inflow amount of black carbon observed at the school A. However, the inflow amount of black carbon at school B was not greatly influenced by the height of the noise barrier. The inflow amount of black carbon at the schools could be changed not only by the height of the noise barrier, but also by the shape, height and position of the noise barrier and the school building.
Supplemental substrates for mushroom cultivation media are potent sources for fungal contamination of indoor environment in cultivation houses. The present study was performed to investigate the presence of harmful fungi in the supplemental materials (beet pulp, cotton seed meal, kapok meal, peat moss, wheat straw) imported from China, Egypt, Germany, Indonesia and Pakistan. Fungal concentration in the supplemental materials ranged from 1.3×102 to 1.8×103 cfu/g. A total of 11 genera and 21 species were identified. Two genera and two species were found in Germany peat moss. In Pakistan wheat straw, three genera and four species were detected. In Egypt beet pulp and China cotton seed meal, four genera and five species and seven genera and ten species were shown, respectively. Among the identified fungi, Acremonium sp., Aspergillus chevalieri, Cryptococcus adeliensis, Eurotium amstelodami, Paecilomyces variotii and Rhodotorula mucilaginosa were known as human pathogens. This study provided evidence that pathogenic yeast and filamentous fungi are present in imported agricultural byproduct materials for mushroom cultivation.
An up-flow botanical bioreactor was proposed as an economical and environmentally-friendly control process to remove the odorants, specifically ammonia and hydrogen sulfide, in exhaust gas. Liriope Platyphylla and Hedera Helix were selected as the test plants, and were put into the lab-scale reactor filled with the ceramic media. During 52 days of operation with ammonia loading of 1.16 g/m3·d, Liriope Platyphylla showed better performance in ammonia removal. Liriope Platyphylla was further tested by the simultaneous loading of 6.96 g/m3·d for ammonia and 1.00 g/m3·d for hydrogen sulfide. Microbial activity in the botanical reactor was greatly enhanced by mixed odorants rather than single odorants, and can contribute to removing odor in the exhaust gas. Biological uptake by plants reached up to 20% of total nitrogen loading to the botanical reactor.
In this study, swine and cattle farms located in Jeollanam-do were selected to analyze and evaluate the components of odorants in livestock facilities. In addition, a preliminary survey of the literature was conducted to establish a sampling and analysis method for phenol and indoles which are major components of odor emissions from livestock facilities, yet are not regulated by the laws. To establish a sampling and analysis method for phenol and indoles, Tedlar bag and Tenax-TA sorbent tube was used as background concentration of blank sample and samples according to the elapsed time. The results obtained indicate the GC/MS analysis with Tenax-TA sorbent tube sampling was an effective method for measuring the compounds of phenol and indoles. In the swine facility, the rankings of the odorants in order, from highest to lowest, were ammonia, sulfuric compounds, phenol/indoles, volatile fatty acids. The main odorants were hydrogen sulfide (41.3%) and 4-methylphenol (p-cresol, 13.9%). In the swine slurry storage, hydrogen sulfide (33.7%), ammonia (18.8%), and 3-methylindole (skatole, 15.7%) were the main odorants, and hydrogen sulfide (31%) and i-valeric acid (32.4%) were the main odorants in the cattle farms.
Adsorption technology can effectively handle the volatile organic compounds (VOCs) from waste gas. However the adsorption of VOCs at elevated temperature (>30oC) and high humidity conditions results in competitive adsorption between VOCs and the moisture. Furthermore, physical adsorption at an elevated temperature is the cause of degradation in the regeneration process performance. In this study, toluene as waste organic solvent in air at elevated temperature and high humidity was used to measure performance. The effects of the SiO2/Al2O3 ratio of zeolites, the adsorbent material coated on adsorption regenerative rotors, on the adsorption performance of toluene with respect to temperature (30~50oC) and relative humidity (50~90%RH) have been investigated. The adsorption of toluene decreased as relative humidity and adsorption temperature rose. The result shows that Htype ZSM5 (SiO2/Al2O3=100) zeolite exhibited the highest adsorption capacity for toluene at elevated temperature and humidity conditions. The physical and chemical adsorption of toluene on acid sites of zeolite were confirmed by this study.
The present study was conducted to investigate the public awareness level of the Korean population on the hazards of radon. Its purpose was to serve as a preliminary study for the development of a risk communication program suited to Korean domestic conditions. An in-house developed questionnaire was used as an awareness surveying tool. Five thousand people (adults) from the general population, randomly selected regardless of their age, academic background, income level, and regional distribution were surveyed. The survey was conducted between December 2015 and February 2016, and completed in a self-reporting format. The survey results showed that public awareness of the radon risk was very low, as indicated by more than roughly 85% of the respondents saying that they did not know what radon was. Moreover, survey results for those who knew what radon was showed a very low level of awareness regarding the physical properties and hazards of radon. Through the findings of the present study, it was confirmed that the awareness of radon hazards among the residents of Korea needs urgent improvement and that the development of a radon risk communication program accounting for age, income, region, occupation, and various information delivery routes is also needed.
The purpose of this study is to investigate and compare the change of wind velocity and processing efficiency of sulfuric compounds and more complex odors. The research was conducted in a facility specializing in odor prevention applications using upgraded existing research equipment (from 30 CMM to 200 CMM) on wastewater treatment. The research equipment was installed with the purpose of removing odor from the wastewater treatment (Pasteur Factory) located in Hoengseong-gun, GangWon. To investigate the treatment efficiency of hydrogen sulfide test samples were evaluated with different blower installation positions and changes in wind speed. The wind speed at the static pressure is about 1.70~2.08 times faster than that of the static pressure, although the blower power is different. The efficacy of sulfur compounds and complex odor treatment was 91.27% and 95.20%, respectively. The study results show that it is necessary to review the design point of wind speed due to the increase in facility scale. In addition, considering the characteristics of complex odor, it is necessary to consider additional surcharges. It was determined that the facility plan for odor prevention in relation to wind velocity will be reexamined. Ongoing research will also be considered to help identify any disadvantages and solutions for the ventilator positioning, which is currently installed in the back.
This study measured and analyzed the heavy metal (Cd, As) content of fine dust in the city of Gwangyang, Jeonnam from September 19 to September 22, 2016. For cadmium, the arithmetic average was 0.21 ng/m3 (0.12~0.49 ng/ m3), which did not exceed the WHO's recommended level. The average of arsenic was 2.41 ng/m3 (0.30~142.08 ng/ m3) and the geometric mean was 11.18 ng/m3, which exceeded the WHO's recommended standard in 16 out of 24 measurements. In the case of cadmium, the CTE of male was 9.22 × 10−8 RME 1.91 × 10−7 and the female CTE was 9.44 × 10−8 RME 1.92 × 10−7, which did not exceed the EPA limit of CTE 2.18 × 10−5 RME 1.51 × 10−4 for men and CTE 2.23 × 10−5 RME 1.51 × 10−4 For women, CTE 2.23 × 10−5 RME 1.51 × 10−4 results were obtained, which exceeded the EPA's recommended limit and also exceeded the maximum allowable limit of 10-4.