Temperature influence on total volatile compounds (TVOCs) inside the car cabin of visible light transmittance

In the automotive industry indoor air quality or Vehicle Indoor Air Quality (VIAQ) are caused by various substances emitted from interior materials inside a vehicle. The volatile organic compounds (VOCs) are an example of emitted substances from the interior materials which is harmful to the human body. As stated by previous researches, there is a strong correlation between the total VOCs emission and interior temperature. This occurs due to the solar radiation through the back window glasses, windscreen and side window glasses. This trapped heat can accelerate the melting process of trim materials such as hard plastic and rubber, thus causing the emission of total VOCs (TVOCs). Therefore, reducing the percentage of visible light transmittance (VLT) will help to reduce radiation process. The aim of this study is to investigate the effect of VLT level on TVOCs emission in the vehicle cabin under static condition (parked and unventilated) and operating condition (driving and air-conditioned). For static condition the result shows that the TVOCs concentration linearly decreases whenever the percentage of VLT level decreases. However, for operating condition the percentage of VLT have less significance after 50 minutes driving time. In conclusion, the VLT levels have a strong relationship to the TVOCs concentration despite after a long driving time

The effect of the composting time on the gaseous emissions and the compost stability in a full-scale sewage sludge composting plant

Volatile organic compounds (VOCs) and ammonia are some of the compounds present in gaseous emissions from waste treatment facilities that contribute to odour pollution. In the present work, the effect of the residence time on the biological stability of raw sludge (RS) composted in dynamic windrows and the gaseous emissions generated were studied at a full-scale composting plant, aiming to provide specific pollutant emission factors and to determine their variability depending on the composting time. Waste stability and emissions analysis considered both a first phase where mixed RS and vegetal fraction (RS - VF) is actively composted in dynamic windrows and a second standard curing phase in turned piles, which lasted 31 days. Two windrows were operated at 4 days of composting time while two other windrows were operated simultaneously at 14 days composting time. Increasing the residence time leads to a better waste stabilization in the first composting phase, providing a 50% reduction ofthe Dynamic Respiration Index. A decrease of the ammonia emission factor was achieved when increasing the composting time (from 168.5 g NH 3 ·Mg −1 RS - VF d −1 to 114.3 g NH 3 ·Mg −1 RS - VF d −1 ), whereas the VOCs emission factor was maintained for the same process conditions (between 26.0 and 28.0 g C-VOC·Mg −1 RS - VF d −1 ). However, an increase of the emission masses of both pollutants was observed (from 0.16 to 0.39 kg tVOCs·Mg −1 RS − VF and from 1.21 to 1.60 kg NH 3 ·Mg −1 RS - VF). Finally, ammonia and VOCs emissions generated at the curing piles were nearly avoided when increasing the composting time of the first phase

Interior Materials Combination and Perceived Indoor Air Quality

The materials used in the buildings, either as surface structural materials or as furnishings, are mostly the sources of indoor air pollution. Interior surfaces are generally accepted as the main source of indoor TVOCs emissions. The poor indoor microclimate quality can cause the sick building syndrome, as well as negatively affects the people activities and wellbeing. In recent years the needs of indoor air quality and building performance improvement have been increasing. The indoor materials impact on perceived indoor air quality for various surface interior materials and its combination was studied within this paper. Traditional and progressive materials comparison reveals new fact regarding the TVOCs concentration. The task of the study was to investigate the possibility using individual material surfaces sorption ability. The chemical analysis and sensory assessments identifies health adverse of indoor air pollutants (TVOCs). Also we can use knowledge about the targeted use of sorption effect already in the building design phase. The results demonstrate the various sorption abilities of various indoor materials as well as various sorption ability of the same indoor material in various combinations

Characterization of odorous compounds and odor load in indoor air of modern complex MBT facilities

Gaseous emissions and chemical compounds responsible for odor nuisance are the most common social concerns arising from modern municipal mechanical-biological waste treatment (MBT) facilities. Regarding to this, an inventory of indoor concentrations of hydrogen sulfide and volatile organic compounds (VOCs) along with odor analyses were carried out at three different full-scale MBT facilities. 48-h profiles of total volatile organic compounds (tVOCs) and hydrogen sulfide were performed in selected areas (reception warehouse, pretreatment, anaerobic digestion and composting areas) and a complete gases and odor characterization were performed at two selected moments of the day according to maximum and minimum tVOCs concentrations, which corresponded to day/night variations. Terpenoids, aromatic hydrocarbons and aliphatic hydrocarbons were the families of VOCs more often detected. The average percentage of contribution of these three VOCs families was 32, 21 and 24%, respectively, while the average percentage of contribution of other VOCs families ranged from 0.2 to 5.5%. A multiple regression method was developed as a simple tool for odor modeling and prediction, showing that 98.5% (p < 0.001) of the variance in odor concentration could be explained by the concentrations of hydrogen sulfide and tVOCs. Results obtained suggested that optimization of indoor ventilation systems and, concomitantly, operational costs of MBT facilities was possible in certain locations where ventilation could be reduced up to 20-25% during night hours

TVOCs and PM 2.5 in Naturally Ventilated Homes: Three Case Studies in a Mild Climate

In southern Europe, the present stock of social housing is ventilated naturally, with practice varying in the di erent seasons of the year. In winter, windows are kept closed most of the day with the exception of short periods for ventilation, whereas the rest of the year the windows are almost permanently open. In cold weather, air changes depend primarily on the air infiltrating across the envelope and when the temperature is warm, on the air flowing in through open windows. CO2, PM2.5, and TVOC concentration patterns were gathered over a year’s time in three social housing developments in southern Europe with di erent airtightness conditions and analyzed to determine possible relationships between environmental parameters and occupants’ use profiles. Correlations were found between TVOC and CO2 concentrations, for human activity was identified as the primary source of indoor contaminants: peak TVOC concentrations were related to specific household activities such as cooking or leisure. Indoor and outdoor PM2.5 concentrations were likewise observed to be correlated, although not linearly due to the presence of indoor sources. Ventilation as presently practiced in winter appears to be insufficient to dilute indoor contaminants in all three buildings, nor does summertime behavior guarantee air quality

일부 도예 작업장의 호흡성 유리규산을 포함한 입자상 물질 및 일산화탄소, 총 휘발성 유기화합물에 관한 연구

학위논문(석사) -- 서울대학교대학원 : 보건대학원 환경보건학과, 2022. 8. 윤충식.연구 배경: 전통적인 도자기를 제조하는 작업장은 원재료 점토와 유약으로 도자기를 빚고, 그것들을 가마에 소성하는 과정에서 건강상에 악영향을 미치는 입자상 물질과 가스상 물질이 발생된다. 하지만, 여러가지 작업공정과 가마 종류별로 수행된 노출평가 연구는 아직까지도 부족한 실정이다. 따라서 본 연구에서는 가마 종류별로 발생하는 일산화탄소와 총 휘발성 유기화합물(TVOCs)를 모니터링 하고, 가마 종류와 작업 공정별로 도예 작업장에서 발생하는 호흡성 유리규산을 포함하는 입경 분포별 입자상 물질의 노출 수준을 평가하는데 목적이 있다. 또한, 입자상 물질들의 노출 수준을 변화시키는 요인들도 평가하고자 한다. 연구 방법: 대한민국에 소재한 소규모 도예 공방, 미술대학교 공예과 실기실, 장작 오름가마와 그곳에서 작업하는 도예가들을 대상으로 연구를 수행하였다. 개인시료는 총분진과 호흡성 분진, 그리고 호흡성 유리규산을 측정하여 분석하였다. 지역 시료로는 각각의 작업 장소와 가마 근처에서, 총분진과 호흡성 분진, 호흡성 유리규산, 10nm~10,000nm의 입경분포를 지닌 입자상 물질, 일산화탄소, TVOCs을 측정하였다. 총분진, 호흡성 분진은 전자 저울을 사용하여 여과지를 중량 하였다. 그리고 호흡성 분진을 포집한 필터는 푸리에 변환 적외선 분광법(FT-IR)를 활용하여 호흡성 유리규산 분석에 사용되었다. 10-10,000 nm 입자 크기 분포를 갖는 입자는 광학 입자 계수기(OPS)와 병렬로 설치된 나노 에어로졸 입경분포 측정기(SMPS)에 의해 분석되었다. 일산화탄소 및 TVOCs는 광이온화 감지기와 실내 공기질 측정기(IAQ-Calc)로 분석되었다. 연구 결과: 세 곳의 도예 작업실에서 측정한 총분진, 호흡성분진, 호흡성 유리규산의 기하평균은 146.46 μg/m3, 49.10 μg/m3, 1.89 μg/m3 이었다. 그 중 4개의 호흡성 유리규산 개인시료의 농도는 ACGIH TLV을 초과했으며, 4개 시료 모두 성형&정형 작업이었다. 소규모 도자기 공방의 전기가마에서 10 nm–420 nm의 직경을 갖는 입자 수 농도는 초벌 소성 중기 동안 수분 배출구가 열려 있을 때(1.61 × 10^5)가 닫혀있을 때(2.16 × 10^4)보다 약 7.5배 더 높았다. 미술대 도예과에서는, 유약 분말을 물과 섞고 드릴로 혼합하는 장소인 유약 벤치(5.61 × 10^4)에서의 입자 수농도(10 nm-420 nm)가 유약 스프레이 부스 (6.73 × 10^3)의 입자 수농도 보다 약 8.3배 높았다. 일산화탄소 농도는 전기산화(초벌 소성)에서 평균과 최고농도 모두 각각 3.55 ppm, 23.7 ppm으로 가장 높았다. 반면에, TVOCs 농도는 장작 가마(2층 ~ 최고층)에서 평균과 최고농도 모두 각각 5,732.31 ppb, 12,034 ppb로 가장 높게 나타났다. 결론: 본 연구를 통해 도자기 제조 공정과 가마 종류별로 일부 입자상 물질의 농도에서 차이가 있는 것과, 호흡성 유리규산을 포함한 입자상 물질, 일산화탄소 및 TVOC가 도예가에게 노출될 수 있음을 확인하였다. 실제로 전기산화가마의 수분배출구 개방 여부, 유약 스프레이 시 국소배기의 작동, 가마에 장작을 넣는 시간 간격 등이 각종 유해물질 농도에 영향을 미칠 수 있음을 확인하였다. 이처럼, 도예 작업 시 입자상 물질 및 유해 가스 등에 노출될 위험성이 높은 바, 적절한 호흡 보호구의 착용과 국소배기장치의 설치가 권장된다.Objective: Ceramics with raw clay and glaze are made in traditional pottery workplaces. When firing them in a kiln, particulate matter and gaseous substances that cause adverse health effects are generated. However, exposure assessment studies of the various pottery manufacturing processes or kiln types are insufficient. Therefore, this study aimed to compare the particulate matter concentrations by particle size distribution and respirable crystalline silica (RCS) generated in pottery workplaces by each kiln type and work process, and assess factors that change the concentration levels of particulate matter, monitor carbon monoxide (CO) and total volatile compounds (TVOCs) generated by each kiln type. Methods: The research was conducted in small-sized pottery workshops in Korea, a college of fine art pottery studio, and an outdoor climbing kiln and included the potters working there. Personal samples for the exposure assessment were collected by measuring total suspended particulates (TSP), respirable suspended particulates (RSP), and RCS. As an area sample, TSP, RSP, RCS, particulates with 10–10,000 nm particle size distribution, CO, and TVOCs were measured for each workplace and pottery manufacturing process. TSP, RSP were analyzed by the gravimetric analysis using an electronic balance for weighing membrane filters. And filters which collected RSP were used for evaluate RCS by fourier transform infrared spectroscopy (FT-IR). Particulates with 10–10,000 nm particle size distribution were analyzed by a scanning mobility particle sizer (SMPS) installed in parallel with the optical particle sizer (OPS). CO and TVOCs were analyzed by a photoionization detector and an indoor air quality meter (IAQ-Calc). Results: The TSP’s, RSP’s, and RCS’s geometric mean, except for background concentration, was 146.46 μg/m3, 49.10 μg/m3, and 1.89 μg/m3, respectively. Among those, four personal RCS samples’ concentration exceeded American conference of governmental industrial hygienists threshold limit values (ACGIH TLV), all of which were shaping and trimming procedures. Particle number concentrations (PNCs) with a diameter of 10 nm–420 nm were approximately 7.5 times higher when the peepholes were left open (1.61 × 10^5) than when they were closed (2.16 × 10^4) during mid-term firing of the electric oxidation kiln of small-sized pottery studio. In addition, the PNC (10 nm–420 nm) in the glaze dipping bench (5.61 × 10^4), where the glaze powder was blended with water and mixed with a drill before the unglazed bisqueware was dipped, was 8.3 times higher than that in the glaze spray booth (6.73 × 10^3) in glaze room of collge of fine arts studio. The CO concentration was the highest in the electric oxidation kiln (when oxidation firing), with average and maximum concentrations of 3.55 ppm and 23.7 ppm, respectively. Conversely, the TVOCs concentration was the highest in the climbing kiln (2nd–top floor), with average and maximum concentrations of 5,732.31 ppb and 12,034 ppb, respectively. Conclusion: We confirmed that some particulate matter concentrations differed with the pottery manufacturing process and kiln type. The results showed that particulates including RCS, CO, and TVOCs could be exposed to potters. Indeed, whether the plugs are opened in the electric oxidation kiln, operation of exhaust vent during glaze spraying, and an time interval of adding firewood to the climbing kiln affect the concentration of various hazardous substances. Since there is a high risk of exposure to particulate matter and harmful gases during pottery manufacturing, wearing appropriate personal protective equipment for potters when shaping and trimming the clay and installing the local exhaust system near kilns or glaze spraying booths is recommended.1. Introduction 1 2. Methods 3 2.1. Workplace description 3 2.2. Sampling and evaluating methods 6 2.2.1. Sampling design 6 2.2.2. Evaluating for TSP, RSP and RCS 7 2.2.3. Real-time measurement of particle number concentration 8 2.2.4. Real-time measurement of CO, TVOCs 8 2.3. Statistical methods 9 3. Results 10 3.1. TSP, RSP, and RCS concentrations between study subjects 10 3.2. Number concentration and size distribution of particulates 16 3.3. Concentrations of CO and TVOCs 19 4. Discussion 20 5. Conclusion 25 References 26 Appendix 29 국문초록 33석

건설업 고위험 직종별 유해인자 노출 평가

학위논문 (박사) -- 서울대학교 대학원 : 보건대학원 보건학과, 2021. 2. 윤충식.건설업은 노동의존도가 매우 높은 산업으로, 건설업 근로자는 작업과정 중 다양한 유해인자에 복합적으로 노출되는 것으로 알려져 있다. 그러나, 작업장 이동이 많고, 단위작업 장소에서의 작업시간이 짧으며, 작업환경이 지속적으로 변화하는 특성으로 인해 노출되는 유해인자의 농도수준 및 특성에 대해서는 잘 알려져 있지 못하다. 이번 연구는 건설업 근로자의 직종별 노출 유해인자를 조사하고, 직업성 암 등 건강장해 발생 위험이 높은 직종(지하 굴착공, 콘크리트 마감공, 방수도장공, 용접공, 아스팔트 도로포장공)을 우선대상으로 선정하여 발암성 물질을 중심으로 유해인자 노출농도 수준 및 농도에 영향을 주는 환경변수 등을 평가하였다. 먼저, 탑다운 공법을 적용한 주상복합 건축물 신축현장 4개소의 지하 굴착작업 중 발생하는 원소탄소 (elemental carbon, EC), 다환방향족탄화수소 (polycyclic aromatic hydrocarbons, PAHs), 호흡성 산화규소 결정체 (respirable crystalline silica, RCS)의 노출농도 수준을 살펴보았다. EC 농도는 권고기준인 20 ㎍/㎥을 초과하는 시료가 전체의 약 50 %를 차지하였다. RCS의 기하평균(geometric mean, GM)농도는 노출기준인 0.05 ㎎/㎥의 1.5배를 초과하였다. 주요 환경변수로 암석지반, 높은 장비 밀집도, 발파작업, 환기조건이 나쁠수록 EC 및 RCS 농도수준이 높은 것을 알 수 있었다. 특히, 작업환경개선이 가장 우선 적용되어야할 대상은 상부가 밀폐된 경암 지반의 현장이었다. 지하 굴착작업장에서 디젤엔진배출물 및 산화규소 노출을 최소화하기 위한 노력으로 작업장 상부를 최대한 개방하여 충분한 환기를 실시하고, 살수를 통한 습식작업환경 조성, 노후 차량의 교체, 차량의 정기 점검 및 유지 보수, 및 저유황유 사용 등의 개선조치가 필요하다. 아파트 건설현장 8개소의 콘크리트 마감작업(할석, 그라인딩, 미장작업)에 대한 RCS 노출 농도를 평가하였다. RCS의 GM 농도는 콘크리트 그라인딩 작업에서 2.06 ㎎/㎥, 할석작업에서 0.12 ㎎/㎥로 노출기준인 0.05 ㎎/㎥의 각 40배 및 2배를 초과하였다. 콘크리트 그라인딩 작업 중 RCS 농도는 계단실 (4.18 ㎎/㎥), 세대내부 (2.76 ㎎/㎥), 지하작업장 (1.30 ㎎/㎥) 등 작업 공간 체적이 작을수록 농도수준이 높음을 알 수 있었다. 작업환경개선이 가장 우선 적용되어야할 대상은 작업공간이 작은 장소에서의 콘크리트 연마작업이었다. 건설현장 콘크리트 마감 작업 중에서 RCS 노출을 저감하기 위해서는 환기캡을 적용한 국소배기장치의 사용, 습식작업 등의 작업환경개선이 시급하며, 공학적 개선과 함께 호흡보호구의 철저한 지급․착용 및 밀착도 검사, 주기적인 건강검진 모니터링이 필요하다. 건설현장 도장작업자에 대한 휘발성 유기화합물(volatile organic compounds, VOCs) 노출수준을 살펴보기 위해 8개 건설현장에서 우레탄 방수작업에 대해 평가하였다. VOCs의 혼합물질 노출지수(exposure index, EI; 노출기준=1)의 GM은 국내 노출기준(Korea occupational exposure limits, KOEL)의 약 78%수준이었으며, KOEL을 초과하는 시료가 전체시료의 약 38.6%로 작업환경관리가 요구되는 수준이다. 더욱이, EI를 미국 ACGIH TLVs에 따라 산출하면, EI의 GM이 1.84로 KOEL의 약 2배 수준으로 매우 높았다. 혼합물질 평가에 가장 큰 영향을 미치는 물질은 톨루엔이었다. 작업별로는 실내 우레탄 프라이머 도포 작업에서 노출농도가 가장 높았다. 건설현장 도장작업자의 건강관리를 위해 도료 구성성분 중 발암성 물질과 생식독성물질은 최대한 유해성이 낮은 물질로 대체하고, 농도수준에 따라 적절한 보호계수를 갖는 개인보호구의 지급 및 착용 및 지속적인 노출평가와 건강검진 실시결과에 대한 사후관리가 필요하다. 또한, 실내 작업의 경우는 환기장치를 가동하고 작업을 진행하여 유기화합물 노출을 최소화 하여야 한다. 건설현장 일반건축물 배관용접공, 화학플랜트 배관용접공, 철골용접공, 소각플랜트 보일러 제작 용접공, 금속마감용접공을 대상으로 용접흄 및 금속류에 대한 노출농도(GM) 수준을 살펴보았다. 용접흄의 농도는 일반건축물 배관공 (4.75 ㎎/㎥)> 철골용접공 (3.77 ㎎/㎥) > 보일러제작용접공 (1.38 ㎎/㎥)> 금속마감용접공 (0.78 ㎎/㎥) > 화학플랜트 배관용접공(0.71 ㎎/㎥) 순으로 높았다. 용접기법에 따른 용접흄 농도는 CO2용접 (2.08 ㎎/㎥) > 피복아크용접 (1.54 ㎎/㎥) > TIG용접 (0.70 ㎎/㎥) 순으로 높았고, 동일한 직종의 일반건축물 배관용접작업에서 지하공간 (7.75 ㎎/㎥)과 지상층 실내공간 (2.15 ㎎/㎥)의 용접흄 농도차이는 약 3.6배로 더욱 커서 작업장 환기조건이 용접흄 농도에 중요한 환경변수 임을 알 수 있었다. 용접작업 위험도가 높은 일반건축물의 배관용접과 철골용접작업, 지하공간에서의 용접작업, CO2 용접작업 등을 수행할 시에는 환기장치 사용과 호흡용 보호구 착용 등 철저한 작업환경관리와 작업 시 아크까지 일정거리 유지, 적정 용접전류 선택 등 용접흄 발생을 최소화할 수 있는 근로자 안전보건교육이 필요함을 알 수 있었다. 아스팔트 도로포장을 실시하는 건설현장 3개소에서 아스팔트 흄(벤젠추출법) 및 다환방향족탄화수소(PAHs) 농도를 직종별로 살펴보았다. 아스팔트 흄(벤젠추출법) 농도의 직종별 차이를 살펴보면, 포장특공 (42.32 ㎍/㎥), 포설장비 운전원 (41.57 ㎍/㎥), 머캐덤 운전원 (31.9 ㎍/㎥), 타이어 운전원 (30.31 ㎍/㎥) 순으로 높았다. 아스팔트 흄은 노출기준 500 ㎍/㎥의 약 10% 수준으로 매우 낮았으나, PAHs의 경우, 대기환경 농도와 비교하면 수백배 높은 농도수준이었으며, 도료, 타르 제조업 등 타 업종과 비교하여 총 PAHs 농도는 낮았으나, 세부물질 중 Benzo(a)pyrene 농도가 상대적으로 높은 특성이 있었다. 또한 아스팔트 도로포장 작업의 경우 주변 건물 및 풍속 등 환경변수에 따른 농도변이가 매우 큰 특성이 있으므로 다양한 작업현장을 대상으로 추가적인 노출평가 연구가 요구된다. 이번 연구를 통해 그동안 잘 알려져 있지 못한 건설업 근로자의 유해인자 및 노출농도 수준을 확인할 수 있었다. 직종별 노출평가 결과에서 대부분의 작업이 노출기준을 초과하여 직업성 암 등 건강장해 발생 위험이 높은 수준임을 확인할 수 있었다. 베이시안(Bayesian) 통계기법을 활용한 평가자료의 95% 상위값이 노출기준을 초과할 확률을 살펴보면, 지하굴착공의 원소탄소 및 산화규소(결정체), 콘크리트 할석, 그라인딩공의 산화규소(결정체), 도장공의 휘발성 유기화합물, 일반건축물 배관용접공 및 철골용접공의 용접흄 농도는 약 5% 이상의 작업자는 노출기준을 초과할 우려가 있음으로 평가되어 작업환경개선이 요구되었다. 또한, 건설현장의 특성상 평가그룹별 농도의 변이수준이 높음을 확인하였으며, 향후 작업환경측정 시 변이를 고려한 적정 시료수, 반복측정 및 유사노출그룹 선정과 추정 상한치 등을 통한 위험수준 평가 적용이 필요함을 알 수 있었다. 평가농도에 영향을 미치는 주요 환경변수는 작업장의 환기조건, 건축재료, 작업방식 등임을 확인하였으며, 직종별 특성에 맞는 지속적인 작업환경개선 노력과 설계단계에서부터 유해인자 노출을 감소시킬 수 있는 공법의 도입 등이 필요하다. 또한, 향후 건설업 특화된 작업환경측정 및 건강관리제도의 개선과 지속적인 노출평가 연구가 요구된다. 이번 연구결과는 건설노동자의 업무상 질병 역학조사 시, 노출농도 예측을 위한 자료로 활용가능하며, 연구결과를 통해 도출된 농도에 영향을 주는 주요 환경변수 및 개선방안에 따라 건설현장 작업환경개선에도 기여할 수 있을 것으로 기대된다.The construction industry is highly dependent upon human labor compared to other industries. Construction workers are exposed to various hazardous substances simultaneously. However, little is known about the exposure level of hazardous substances due to the characteristics of frequent workplace shifts, changes in the working environment, and the multi-level subcontractor structure. This study was aimed at (a) identifying the exposure hazards of construction workers, (b) conducting an exposure assessment of carcinogenic substances for high-risk construction workers (excavation workers, concrete finishers, waterproof painters, welders, and asphalt road pavers), and (c) determining the variables most affecting hazardous substances concentrations and work environment improvement methods for construction workers. Identification of the exposure hazards among construction workers by job type The exposure hazards of 27 construction jobs were identified and summarized through a literature review and walk-through survey. Construction workers were exposed to noise, vibrations, ultraviolet rays, solar radiation, various types of dust (cement, concrete, wood, glass wool, mineral, and gypsum), and chemicals such as crystalline silica, diesel engine exhaust, asphalt fumes, asbestos, lead, chromium, epoxy/urethane, isocyanate, carbon monoxide, metal fumes, and volatile organic compounds. The most frequently exposed seven hazards were noise, vibrations, solar radiation, crystalline silica, cement/concrete dust, metal fumes, and volatile organic compounds. As for the exposure characteristics, construction workers were exposed to various hazards simultaneously, including carcinogenic substances and those with adverse reproductive effects. Among construction workers, the job types with the highest risk of exposure to carcinogens, and in which occupational cancer has been reported, were excavation workers, concrete finishers, painters, welders, and asphalt road pavers. Exposure assessment of elemental carbon, polycyclic aromatic hydrocarbons and respirable crystalline silica among underground excavation workers The concentration of elemental carbon (EC), organic carbon (OC), and total carbon (TC) (n = 105), polycyclic aromatic hydrocarbons (PAHs) (n = 50), respirable dust (RD) (n = 34) and respirable crystalline silica (RCS) (n=34) were evaluated inside and outside the excavator at an underground excavation worksite in four different construction sites. EC, OC, and TC were collected on a quartz filter and analyzed using the thermal optical transmittance method. PAHs were collected on a polytetrafluoroethylene (PTFE) filter with an XAD-2 tube and analyzed using liquid chromatography with a fluorescence detector. RD and RCS were collected on a polyvinyl chloride (PVC) filter with aluminum cyclone and analyzed using Fourier-transform infrared spectroscopy. The geometric mean (GM) of respirable EC, OC, TC, total PAHs, RD, and RCS were 8.69 ㎍/㎥, 34.32 ㎍/㎥, 44.96 ㎍/㎥, 6.82 ㎍/㎥ 0.13 ㎎/㎥ and 0.02 ㎎/㎥ inside the excavator and 33.20 ㎍/㎥, 41.53 ㎍/㎥, 78.21 ㎍/㎥, 3.93 ㎍/㎥, 0.9 ㎎/㎥, and 0.08 ㎎/㎥, respectively, outside the excavator at the underground excavation worksite. The EC concentrations exceeded the recommended exposure limits as of 20 ㎍/㎥ accounted for about 50% of the total samples, and the GM of RCS outside the excavator exceeded 1.5 times the occupational exposure limit (OEL) of 0.05 ㎎/㎥. The worksites with hard rock ground, higher vehicle density, blasting work, and enclosed environments had higher worker exposure to EC than the other sites (p < 0.05). The most influential variables were the ground type and ventilation condition. In particular, in high-risk excavations in rocky ground and enclosed environments, more effort is needed to improve the working environment by introducing water-spraying facilities and supplying fresh air and ventilation. Furthermore, the replacement of old vehicles, regular vehicle maintenance, and the use of low sulfur oil is suggested. Exposure assessment of RD and RCS among concrete finishing workers The concentration of RD and RCS (n = 129) and the size distribution of the particles (n = 6) using a cascade impactor were evaluated at eight apartment complex construction sites. RD and RCS were collected on PVC filters with aluminum cyclone and analyzed using Fourier-transform infrared spectroscopy. The GM of RCS in concrete grinding (2.06 ㎎/㎥) and concrete chipping (0.12 ㎎/㎥) exceeded 40 times and two times the OEL of 0.05 ㎎/㎥, respectively. The highest concentration of RCS in concrete grinding work was found in the staircases (4.18 ㎎/㎥), followed by the inside walls of the apartment units (2.76 ㎎/㎥), underground parking lots (1.30 ㎎/㎥), and exterior walls (0.89 ㎎/㎥). The GM of RD from concrete chipping, grinding, and plastering was 1.78 ㎎/㎥, 49.96 ㎎/㎥, and 0.37 ㎎/㎥, respectively. The mass fraction of inhalable, thoracic, and respirable crystalline silica from concrete chipping was 73.9%, 40.2%, and 17.9% and 76.0%, 46.3%, and 19.7% from concrete grinding, respectively. The highest RCS concentration was reported in concrete grinding tasks, and the smaller the space, the higher the concentration. The most influential variables were the type of task and size of the workplace. During concrete grinding work, multiple control methods must apply to improve the work environment such as local exhaust ventilation system or water-spraying facilities targeting fine-dust (less than 10 ㎛), simultaneously with the application of high-efficiency respirators. Exposure assessment of total volatile organic compounds among construction waterproofing painters The concentration of total volatile organic compounds (TVOCs) in waterproof painting work was monitored at eight construction sites using an organic vapor monitor (n = 88). Gas chromatography with flame ionization detection was used to identify and quantify the individual organic chemicals. The GM of the TVOCs exposure index (EI, OEL = 1) by work type was the highest when primer roller painting (1.2), followed by urethane resin spread painting (0.85), workplace area samples (0.83), mixing paint (0.53), and assisting the painter (0.35). The GM of the TVOCs EI by workplace was highest in the bathroom (1.4), followed by the swimming pool (1.37), pilot floor (0.89), ground parking lot (0.82), and rooftop (0.57). From this study, the GM of the TVOCs EI was about 78% the level of the Korea OEL (KOEL), and 38.6% of the total samples exceeded the OEL. However, when calculating the EI, according to the ACGIH-TLVs, the GM of TVOCs EI was 1.84, which was more than twice as high as when the KOEL was applied. The highest TVOCs concentration was reported in primer painting tasks in an indoor workplace. The most influential variables were the work environment (indoor vs. outdoor) and the solvent content of the paint. Indoor painting work must apply a ventilation system, and personal protective devices with an appropriate protection factor, and efforts are needed to substitute paints with fewer toxic substances. Exposure assessment of welding fumes and metals among construction welders. The concentration of welding fumes and metals (n = 206) was evaluated using PVC filters with gravimetric analysis and inductively coupled plasma at eight construction sites, including three apartments, two offices, two plant buildings, and one hospital. Among the different welding tasks, the welding fume exposure was the highest for general building pipefitters (4.75 ㎎/㎥), followed by ironworkers (3.77 ㎎/㎥), boilermakers (1.38 ㎎/㎥), metal finishing welders (0.78 ㎎/㎥), and chemical pipefitters (0.71 ㎎/㎥). Among the different welding techniques, welding fume concentrations were highest when CO2 welding (2.08 ㎎/m3), followed by shield metal arc welding (SMAW, 1.54 ㎎/㎥), and tungsten inert gas welding (TIG, 0.70 ㎎/㎥). Among the different workplaces, welding fume concentrations were highest at the underground workplace (7.75 ㎎/㎥) followed by the ground level workplace (2.15 ㎎/㎥). In particular, high-risk welding tasks as general building pipefitters and ironworkers, underground welding work, and CO2 welding techniques require more attention to occupational health management, including air supply and exhaust systems, and worker training on welding fume characteristics by welding base material and welding methods. Exposure assessment of asphalt fumes and PAHs among road pavers. The concentration of asphalt fume (benzene soluble, n = 42) and PAHs (n = 41) was analyzed at three asphalt road pavement construction sites. Asphalt fumes were sampled using PTFE filters. PAHs were sampled using an XAD-2 tube with a glass fiber filter and analyzed using liquid chromatography with fluorescence detection. The exposure to asphalt fumes as benzene soluble aerosols was highest to road pavers (42.32 ㎍/㎥), followed by paver finisher operators (41.57 ㎍/㎥), macadam roller operators (31.9 ㎍/㎥), and tire roller operators (30.31 ㎍/㎥). The most influential variables were the asphalt temperature, the installation of hopper ventilation systems in the paver finisher, and the surrounding building conditions. The benzo(a)pyrene equivalent concentration (BaPeq) was 2.81 for paver finisher operators, 2.07 for road pavers, 0.41 for tire roller operators, and 0.25 for macadam roller operators. The BaPeq values for asphalt road paving workers was higher than that for workers in other PAHs exposure occupations even though at lower total PAHs concentrations. This study confirmed the carcinogenic exposure hazards of asphalt road paving workers. This study identified hazardous substance exposure among construction workers. Construction workers were exposed to various hazards simultaneously. The exposure assessment of construction workers demonstrated that excavation workers (respirable EC and RCS), concrete finishers (RD and RCS), construction painters (TVOCs), and welders (welding fume for pipefitters, boilermakers, and ironworkers) had possibilities of at least more than 5% of the exposure evaluation samples exceeded the exposure limits and their work environment was evaluated as poorly controlled. Efforts are needed to eliminate hazards during design, substitute with less toxic materials and processes, remove workers from hazardous work, select appropriate equipment, reduce the time exposed to hazards, wear protective equipment and conduct regular health checks and concentration monitoring. The characteristics of the exposure in the construction industry showed large day-to-day variations due to the mobile and varied tasks. Therefore, in the future, it is necessary to apply weights for variability when evaluating the work environment monitoring results for construction workers and manage the hazard concentration within the exposure limits. These variations should be applied to the decisions regarding the appropriate sample number, homogeneous exposure groups and the estimated upper limit of concentrations for risk assessment. This research data can be used to estimate the hazards exposure levels of construction workers when adjudicating occupational disease in health compensation insurance claims, and can contribute to improving the work environment at construction sites.1. Introduction 1 1.1. Characteristics of construction workers 1 1.2. Construction job types and hazards 3 1.3. High-risk construction workers 9 1.4. Research scope and overview 17 1.5. Objectives 19 2. Exposure Assessment of Elemental Carbon, Polycyclic Aromatic Hydrocarbons and Respirable Crystalline Silica among Underground Excavation Workers 20 2.1. Introduction 20 2.2. Materials and methods 23 2.3. Results 29 2.4. Discussion 46 2.5. Conclusions 53 3. Exposure Assessment of Respirable Dust and Crystalline Silica among Concrete Finishing Workers 54 3.1. Introduction 54 3.2. Materials and methods 56 3.3. Results 62 3.4. Discussion 74 3.5. Conclusions 77 4. Exposure Assessment of Total Volatile Organic Compounds among Construction Painters 84 4.1. Introduction 84 4.2. Materials and methods 85 4.3. Results 90 4.4. Discussion 100 4.5. Conclusions 103 5. Exposure Assessment of Welding Fumes and Metals among Construction Welders 104 5.1. Introduction 104 5.2. Materials and methods 106 5.3. Results 109 5.4. Discussion 129 5.5. Conclusions 133 6. Exposure Assessment of Asphalt Fumes and Polycyclic Aromatic Hydrocarbons among Road Pavers 134 6.1. Introduction 134 6.2. Materials and methods 136 6.3. Results 139 6.4. Discussion 147 6.5. Conclusions 151 7. Summary of conclusions 152 References 167 Appendix 185 국문초록 219Docto

Emissions of total volatile organic compounds during the digital printing process

The impact of the type of digital machine on increasing of total volatile organic compounds (TVOCs) in the ambient air of the digital printing office was analysed in this study. For that purpose, the TVOCs concentrations in gas samples were measured by mobile gas chromatograph Voyager-Photovac. The cumulative concentrations values of TVOCs for the single-color digital machine were in the range from 0.56 to 5.90 ppm and almost 4 and 25 times below compared to the same values for the four-color digital machine (14.01 - 24.84 ppm). The obtained results could be useful for the future risk assessment of indoor exposure of TVOCs, and for the creation of printing indoor air quality guidelines of the Republic of Serbia

Analisis Karakteristik Vocs (Volatile Organic Compounds) Pada Asap Kebakaran Lahan Gambut Fase Pembaraan (Smouldering) Dan Rekomendasi Pencegahan Kebakaran Lahan Gambut (Studi Kasus: Kabupaten Siak Dan Kabupaten Kampar Provinsi Riau)

Salah satu sumber pencemaran udara adalah pembakaran biomasa (biomass burning). Di Indonesia, sulitnya mencari lahan untuk kegiatan perladangan menyebabkan sebagian masyarakat mulai beralih memanfaatkan lahan gambut untuk areal pertanian. Sebagian masyarakat mengambil jalan praktis untuk membuka areal pertanian dengan membakar lahan gambut. Kebakaran lahan gambut khsusnya fase smouldering menghasilkan lebih banyak gas berbahaya seperti volatile organic compounds (VOCs). Provinsi Riau di Indonesia merupakan salah satu provinsi yang sering mengalami kebakaran lahan gambut selama musim kemarau. Tujuan dari penelitian ini yaitu mengidentifikasi VOCs yang diemisikan dari kebakaran lahan gambut (smouldering fire) dengan cara sampling langsung di titik api (sumber emisi) di Provinsi Riau tepatnya di Desa Langkai Kabupaten Siak dan Desa Rimbo Panjang Kabupaten Kampar, Indonesia. Dari hasil identifikasi terdapat 15 VOCs yang belum pernah teridentifikasi sebelumnya yaitu Hydrazinebenzene, 1-Propanethiol, Cholestadiene, Cholesteryl Butyrate, Cholesteryl Benzoate, 2-Ethyl Nitrobenzene, 1,2,3-Benzotriazin-4(3H)-One, Nonadecane, 2-Ethylacridine, Cholesterol Acetate, Hexacosane, 2-Nitrobenzaldehyde, 2-Pyridinepropanoic Acid, 4-Nitrobenzohydrazide dan Cholesteryl Caprate. Kemudian diketahui terdapat peningkatan persentase VOCs di Desa Langkai Kabupaten Siak dan Desa Rimbo Panjang Kabupaten Kampar jika dibandingkan dengan VOCs pada background. Konsentrasi maksimum TVOCs di Kabupaten Siak sebesar 391.880 µg/m3 sedangkan di Kabupaten Kampar sebesar 195.940 µg/m3. Konsentrasi TVOCs di Kabupaten Siak 130,63 kali lebih besar dibanding baku mutu yang ada, sedangkan di Kabupaten Kampar 65,31 kalinya. 4. Rekomendasi yang diberikan untuk pencegahan kebakaran lahan gambut dimasa mendatang berupa manajemen hidrologi di lahan gambut dengan cara penyekatan parit-parit eksisting (canal blocking) untuk mengatur ketinggian muka air tanah dan penanaman vegetasi tahan api di sekeliling areal pertanian yang tetap menghasilkan nilai ekonomis seperti pisang, pinang dan pepaya sebagai sekat bakar buatan

Multipoint characterization of the emission of odour, volatile organic compounds and greenhouse gases from a full-scale membrane-based municipal WWTP

Altres ajuts: Acord transformatiu CRUE-CSICDifferent environmental and social concerns can arise due to the generation of gaseous emissions during the treatment of urban wastewater. However, there is not an extensive knowledge about which are the main potential odour and greenhouse gas (GHG) emission sources in a wastewater treatment plant (WWTP) and their variability. In this study, a multipoint characterization of the gaseous emissions generated in a full-scale municipal WWTP located in Barcelona was conducted, aiming at identifying the main odour and GHG emission sources. The WWTP under study treats an average inlet flow of 33,000 m3 d−1 using a Ludzack-Ettinger system with Membrane BioReactor (MBR) technology, and it has installed a gas caption and treatment system consisting of a biotrickling filter followed by a conventional biofilter to treat part of the off-gases produced during the wastewater treatment. For this work, gaseous emissions characterization campaigns were conducted to assess the proper performance of the gas treatment unit and to estimate the emission factors referred to odorants and GHGs for the different emission sources and to assess the proper performance of the gas treatment system. Besides, a chemical characterization of the different volatile organic compounds (VOC) present in the gaseous emissions was performed through TD-GC/MS. The main potential odour sources were the reception tank, the barscreens building and the primary settler, where odour concentrations were in the range of 1300 and 2600 ou·m−3. Moreover, GHG emissions were found during the primary treatment and in the MBR units, ranging from 2.21 to 68,217.13 mg CO2eq·m−3. Different VOCs such as aromatic hydrocarbons, alkanes and ketones were found in the gaseous emissions with a high variability among all the emission sources. The results obtained are valuable indicators that can be used to develop odour and GHG mitigation strategies in WWTPs and to estimate the environmental impact of these facilities