Characterization of emissions from a desktop 3D printer and indoor air measurements in office settings

Emissions from a desktop 3D printer based on fused deposition modeling (FDM) technology were measured in a test chamber and indoor air was monitored in office settings. Ultrafine aerosol (UFA) emissions were higher while printing a standard object with polylactic acid (PLA) than with acrylonitrile butadiene styrene (ABS) polymer (2.1 × 10⁹ vs. 2.4 × 10⁸ particles/min). Prolonged use of the printer led to higher emission rates (factor 2 with PLA and 4 with ABS, measured after seven months of occasional use).

UFA consisted mainly of volatile droplets, and some small (100–300 nm diameter) iron containing and soot-like particles were found. Emissions of inhalable and respirable dust were below the limit of detection (LOD) when measured gravimetrically, and only slightly higher than background when measured with an aerosol spectrometer. Emissions of volatile organic compounds (VOC) were in the range of 10 µg/min. Styrene accounted for more than 50% of total VOC emitted when printing with ABS; for PLA, methyl methacrylate (MMA, 37% of TVOC) was detected as the predominant compound. Two polycyclic aromatic hydrocarbons (PAH), fluoranthene and pyrene, were observed in very low amounts. All other analyzed PAH, as well as inorganic gases and metal emissions except iron (Fe) and zinc (Zn), were below the LOD or did not differ from background without printing.

A single 3D print (165 min) in a large, well-ventilated office did not significantly increase the UFA and VOC concentrations, whereas these were readily detectable in a small, unventilated room, with UFA concentrations increasing by 2,000 particles/cm³ and MMA reaching a peak of 21 µg/m³ and still being detectable in the room even 20 hr after printing.     

Characterization of indoor air contaminants in a randomly selected set of commercial nail salons in Salt Lake County,Utah, USA

Air samples were collected in 12 randomly selected commercial nail salons in Salt Lake County, Utah. Measurements of salon physical/chemical parameters (room volume, CO₂ levels) were obtained. Volatile organic compound (VOC) concentrations were collected using summa air canisters and sorbent media tubes for an 8-h period. Multivariate analyses were used to identify relationships between salon physical/chemical characteristics and the VOCs found in the air samples. The ACGIH^® additive mixing formula was also applied to determine if there were potential overexposures to the combined airborne concentrations of chemicals monitored. Methyl methacrylate was detected in 58% of the establishments despite having been banned for use in nail products by the state of Utah. Formaldehyde was found above the NIOSH REL^® (0.016?ppm) in 58% of the establishments. Given the assortment of VOCs to which nail salon workers are potentially exposed, a combination of engineering as well as personal protective equipment is recommended.     

Fume emissions from a low-cost 3-D printer with various filaments

3-D printing is an additive manufacturing process involving the injection of melted thermoplastic polymers, which are then laid down in layers to achieve a pre-designed shape. The heated deposition process raises concerns of potential aerosol and volatile organic compounds (VOC) emission and exposure. The decreasing cost of desktop 3-D printers has made the use of 3-D printers more acceptable in non-industrial workplaces lacking sufficient ventilation. Meanwhile, little is known about the characteristics of 3-D printing fume emission. The objective of this study was to characterize aerosols and VOC emissions generated from various filaments used with a low-cost 3-D printer in an environmental testing chamber. A pre-designed object was printed in 1.25 hours using eight types of filaments. A scanning mobility particle sizer and an aerodynamic particle sizer were employed to measure the particle size distribution in sub-half-micron fraction (<0.5 µm) and super-half-micron fraction (0.5–20 µm), respectively. VOC concentration was monitored real-time by a photoionization detector and sampled with a tri-sorbent thermal desorption tube, and analyzed by thermal desorption gas chromatography mass spectrometry (TD-GC/MS). Results showed high levels of fume particles emission rate (1.0 × 10⁷ to 1.2 × 10¹⁰ #/min) in the sub-half-micron range with mode sizes of 41–83 nm. Particle concentrations peaked during the heat-up and solid layer printing periods. Total VOC concentration in the chamber followed a first-order buildup, with predominant VOC species in the chamber were breakdown and reaction products of the filaments, such as styrene from ABS filaments. These findings and exposure scenario estimation suggest that although the VOC concentrations were much lower than occupational exposure limits, particles with size less than micron might be a concern for users of low-cost 3-D printers due to high respirablity, especially if used in settings without proper guidance and engineering control.     

装修所致室内空气污染对健康的影响

目的通过对新装修住宅的室内空气质量检测和居民健康状况调查,研究室内空气污染物对居民健康的危害。方法检测159户新装修6月～1年的居室室内空气中甲醛、总挥发性有机物(TVOC)、氨和放射性氡的浓度,并用问卷调查居民的健康状况。以各个污染物浓度是否超过国家标准分组分析其对居民健康的影响。结果超标组和达标组室内空气中甲醛浓度分别为(0.170±0.075)mg m3,(0.064±0.022)mg m3;TVOC超标组和TVOC达标组室内空气中TVOC浓度分别为(2.033±1.161)mg m3,(0.271±0.142)mg m3。甲醛超标组居民疲劳、恶心、眼部刺激症状、鼻部刺激症状、喉咙干燥、皮肤干燥、皮肤骚痒、皮肤红肿的阳性率均明显高于甲醛达标组(均P<0.05)。TVOC超标组居民恶心、皮肤骚痒、胸闷气短3个指标阳性率明显高于TVOC达标组(均P<0.05)。结论装修可致室内空气中甲醛和TVOC超标,并可引起明显居民恶心、眼部刺激症状和皮肤刺激等症状,严重损害了居民健康。     

Symptoms of Mothers and Infants Related to Total Volatile Organic Compounds in Household Products

The authors sought to determine whether reported symptoms of mothers and infants were associated significantly with the use of household products that raised indoor levels of total volatile organic compounds (TVOC_s). Data collected from 170 homes within the Avon Longitudinal Study of Parents and Children (ALSPAC: a large birth cohort of more than 10,000) had determined which household products were associated with the highest levels of TVOC_s. The latter data were collected over a period that approximated 6 mo of pregnancy and the infants' first 6 mo of life. This paper presents (a) the mothers' self-reports of the use of these products in their homes and (b) self-reported medical symptoms of mothers and infants postnatally. Higher TVOC levels were associated with air freshener and aerosol use. Infant diarrhea and earache were statistically significantly associated with air freshener use, and diarrhea and vomiting were significantly associated with aerosol use. Headache experienced by mothers 8 mo after birth was significantly associated with the use of air fresheners and aerosols; maternal depression was significantly associated with the use of air fresheners. The results of the study suggest a link between the use of products that raise indoor levels of TVOC_s and an increased risk of certain symptoms among infants and their mothers.     

二次热解吸毛细管气相色谱法同时测定装修居室内空气中31种挥发性有机化合物

目的建立二次热解吸毛细管气相色谱同时测定装修居室内空气中31种挥发性有机化合物的方法。方法采用Tenax TA吸附管采样,二次热解吸毛细管色谱柱分离,FID检测器检测。结果 31种有机化合物在色谱柱可实现良好的分离;各化合物的重现性实验显示RSD均在10%以内;回归方程的相关系数均大于0.99;最低检出限可达1ng/μl的浓度水平;回收率为83.2%～106%。结论该方法适合同时检测装修居室内空气中31种挥发性有机化合物。     

室内化学品中挥发性有机化合物的挥发特征

用气相色谱顶空分析方法和气相色谱—质谱联机分析鉴定了８种室内化学品中挥发性有机化合物成分，包括油漆、地板蜡、地板清洁保护剂、彩色涂料、空气清新剂、壁纸胶等。每种材料经ＧＣ—ＭＳ鉴定出３～３０种化合物，各种材料挥发性有机物的种类、数量及挥发速率各不相同。挥发出的有机物包括烷烃、烯烃、醇、醛、醚、酯以及苯系物。测试小室动态试验结果表明，油漆中挥发性有机物流出浓度与时间的关系符合二项指数方程。     

Occupational exposure to gaseous and particulate contaminants originating from additive manufacturing of liquid,powdered, and filament plastic materials and related post-processes

The aim of this study was to measure the concentrations of gaseous and particulate contaminants originated from additive manufacturing operations and post-processes in an occupational setting when plastics were used as feedstock materials. Secondary aims were to evaluate the concentration levels based on proposed exposure limits and target values and to propose means to reduce exposure to contaminants released in additive manufacturing processes. Volatile organic compounds were sampled with Tenax TA adsorption tubes and analyzed with a thermo desorption gas chromatography-mass spectrometry instrument. Carbonyl compounds were sampled with DNPH-Silica cartridges and analyzed with a high-performance liquid chromatography device. Particles were measured with P-Trak instrument and indoor air quality was sampled with IAQ-Calc instrument. Dust mass concentrations were measured simultaneously with a DustTrak DRX instrument and IOM-samplers. Particle concentrations were highest (2070-81 890 #/cm³ mean) during manufacturing with methods where plastics were thermally processed. Total volatile organic compounds concentrations, in contrast, were low (113–317 µg/m³ mean) during manufacturing with such methods, and vat photopolymerization. However, total volatile organic compounds concentrations of material jetting and multi jet fusion methods were higher (1,114–2,496 µg/m³ mean), perhaps because of material and binder spraying, where part of the spray can become aerosolized. Chemical treatment of manufactured objects was found to be a severe volatile organic compounds source as well. Formaldehyde was detected in low concentrations (3–40 µg/m³) in all methods except for material jetting method, in addition to several other carbonyl compounds. Notable dust concentrations (1.4–9.1?mg/m³) were detected only during post-processing of powder bed fusion and multi jet fusion manufactured objects. Indoor air quality parameters were not found to be notably impacted by manufacturing operations. Only low concentrations (below 2?ppm) of CO were detected during several manufacturing processes. All studied additive manufacturing operations emitted potentially harmful contaminants into their environments, which should be considered in occupational additive manufacturing and workplace design. According to the measured contaminant levels it is possible that adverse additive manufacturing related health effects may occur among exposed workers.     

用VEF值评价地铁车站内挥发性有机物的污染水平

[目的 ]评价地铁车站内站台和站厅挥发性有机物 (VOCs)的污染水平 ,并判断来源。 [方法 ]用气相色谱质谱联用仪对地铁车站站台和站厅挥发性有机物浓度进行测定 ,并用挥发性有机物富集指数 (VEF)进行分析。 [结果 ]两车站站台和站厅监测点白天及夜晚的CO2 浓度差异存在显著性 (P <0 .0 1) ,监测点白天和夜晚的VOCs浓度差异无显著性 (P >0 .0 5 )。地铁车站内VOCs的主要来源来自其自身室内排放源 ,室外污染物浓度及通风状况等可能对室内VOCs有影响。 [结论 ]地铁车站内存在VOCs污染 ,用VEF评价地铁车站内VOCs污染状况 ,能较简便、准确地反映其污染物来源 ,并可比较不同车站之间VOCs的浓度水平     

室内环境空气中VOCs及醛酮类污染调查

目的调查新建校舍室内空气中挥发性有机化学物质(VOCs)和甲醛(HCHO)等醛酮类化学物质污染现状,探讨污染的动态变化和危险性。方法以气相色谱-质谱法分析室内空气中VOCs污染水平,应用高效液相色谱法(HLPC)法检测空气中醛酮类物质,以观察污染的变化趋势。结果3种用途校舍使用初期,室内空气中13项VOCs指标均有不同程度检出,其中甲苯污染为主,占检出VOCs的90%以上,最高达3 044μg/m³。室内空气中醛酮类物质呈多态样变化,甲醛污染水平以8月最高(230μg/m³),1年后降至使用初期的60%,呈伴时间推移逐渐降低的趋势,甲醛的释放与室温变化呈正相关(r>0.6410,P<0.01,n=13);使用初期室内空气中丙酮和乙醛最高污染浓度分别为669和134μg/m³;1年后降至52和49μg/m³以下。结论校舍使用初期室内空气中VOCs和醛酮类污染普遍存在。空气中甲醛随使用时间的延长呈现伴夏季升高的螺旋样下降趋势;丙酮和乙醛呈波浪样下降;VOCs的污染水平使用初期最高,但下降较快,1个月后至初始的1/10~1/20。     

Response of Human Mucociliary Clearance to Acute Alcohol Administration

To determine whether alcohol inhibits mucociliary clearance in humans, the clearance of deposited radiolabelled particles from the lung was measured in 12 volunteers. On one study day, immediately after inhalation of aerosol, the subject ingested ethyl alcohol (0.5 g/kg) in orange juice producing an average alcohol level at 1 hr of 68±8 mg/dl. On the other study day, orange juice alone was injested. The initial deposition of aerosol and sequential measurements of lung retention were made during 4.7 hr and again at 24 hr using a gamma camera. Aerosol deposition patterns were reproducible within subjects. Group average percent bronchial retention during a 4.5-hr period was not significantly different between the control and the alcohol studies, but the variance in the alcohol studies during 0.5–4.5 hr was significantly greater (P<.001). Comparison of data to a previous study group of matched control subjects confirmed an increased variability in clearance after alcohol. Thus, acute alcohol ingestion, at levels similar to those achieved during social drinking, alters mucociliary clearance, but direction and magnitude of the changes differ among individuals.     

房屋装修过程中室内空气污染物的动态变化

[目的]观察房屋装修过程中室内空气主要污染物的动态变化。[方法]选择一套装修中的普通民宅为观察对象,分别于装修前后不同阶段7次采集室内空气样本,采用分光光度法及气相色谱法分析样本,动态观察空气中甲醛、苯及苯系物、总挥发性有机物（TVOC）等污染物的浓度变化。[结果]参照《室内空气质量标准》（GB／T18883-2002）,房屋在常规装修过程中超标的主要污染物为二甲苯（为标准限值0．20mg／m^3的5．0—75．0倍）、TVOC（为标准限值0．60mg／m^3的12．0—79．0倍）和甲醛（为标准限值0．10mg／m^3的1．4—4．0倍）,其中二甲苯和TVOC主要来源于油漆稀释剂,甲醛主要来源于墙面乳胶漆以及家具板材所用胶黏剂;在时间上以油漆喷涂、乳胶漆滚涂以及家具进场后污染最为严重。[结论]室内装修过程中挥发性污染物超标严重,主要超标物质为二甲苯、TVOC和甲醛。污染物浓度值与通风状况、装修时间密切相关。监测结果表明,装修结束后通风5个月基本可使室内污染物浓度降低到标准限值之下。     

Development of the chemical exposure monitor with indoor positioning (CEMWIP) for workplace VOC surveys

The purpose of this article was to research and develop a direct-reading exposure assessment method that combined a real-time location system with a wireless direct-reading personal chemical sensor. The personal chemical sensor was a photoionization device for detecting volatile organic compounds. The combined system was calibrated and tested against the same four standard gas concentrations and calibrated at one standard location and tested at four locations that included the standard locations. Data were wirelessly collected from the chemical sensor every 1.4 sec, for volatile organic compounds concentration, location, temperature, humidity, and time. Regression analysis of the photo-ionization device voltage response against calibration gases showed the chemical sensor had a limit of detection of 0.2 ppm. The real-time location system was accurate to 13 cm ± 6 cm (standard deviation) in an open area and to 57 cm ± 31 cm in a closed room where the radio frequency has to penetrate drywall-finished walls. The streaming data were collected and graphically displayed as a three-dimensional hazard map for assessment of peak exposure with location. A real-time personal exposure assessment device with indoor positioning was practical and provided new knowledge on direct reading exposure assessment methods.     

装修居室内空气污染对成人心理健康影响

目的了解装修居室内空气污染对成人心理健康状态的影响。方法对近5年内有装修史的224户家庭进行室内甲醛和总挥发性有机物（TVOC）的检测,首次采用Derogatis氏90项症状自评量表（SCL-90）对其家庭成人进行心理健康状态测试,并对各种指标进行统计分析。结果224户装修居室内空气中甲醛或TVOC超标的住宅有103户,超标率46.0%。共调查家庭成人350人,其SCL-90量表得分显示,阳性项目数（19.57±13.32）显著低于国内常模;9项因子均分在1.27~1.71之间,所有因子中躯体化、强迫症状和焦虑症状等3个因子的平均得分均高于全国常模。对室内污染物超标的103户成年居民158人调查显示,异常项目检出率排在前4位因子依次是躯体化、强迫症状、抑郁症状和焦虑症状。超标组各因子得分均高于非超标组,其中除人际关系、恐怖症状外,其余7个因子及阳性项目数与非超标组差异有统计学意义（P〈0.05）。结论室内空气污染可能是影响居民心理健康的因素之一。     

室内不同有机污染物浓度下人体神经行为功能的改变

[目的]了解室内空气中有机污染浓度对人体生理功能的影响。[方法]选择新装修三星宾馆、装修一年的二星宾馆、无装修的招待所,以学校教室作为对照,测定室内有机污染物,并对在此环境下工作不超过一个月的人员进行神经行为功能核心测试（NCTB）,分析它们之间的关系,以确定室内空气中有机污染浓度对人体生理功能的影响。[结果]室内空气有机污染物可造成人体神经行为功能损害,污染物浓度越高则神经行为功能越差。[结论]建议降低现有《公共场所卫生标准》中规定的公共场所甲醛限量水平。     

Occupational asthma and rhinitis caused by 1,2-benzisothiazolin-3-one in a chemical worker

We report a case of occupational asthma and rhinitis causedby inhalation of 1,2-benzisothiazolin-3-one, an additive usedas a microbicidal in detergent production, in a 26-year-oldman employed in a chemical factory producing detergents. Thesubject's task consisted of pouring raw materials into the recipientof a machine which mixed the substances. Two months after thebeginning of this job the patient complained of rhinitis andasthma at the workplace. The specific challenge test with 1,2-benzisothiazolin-3-one,one of the raw materials to which the subject was exposed, provokedan immediate prolonged asthmatic response and nasal symptoms,whereas exposure to other agents (e.g., -amylase, alcalase orbezalkonium chloride) to which the patient was also exposedat work did not. To our knowledge this is the first case ofoccupational asthma and rhinitis caused by this compound.     

Anosmia in association with occupational use of a waterproof coating chemical

A case of acute permanent anosmia is described in a renovation worker during exposure to a waterproof coating chemical. The chemical consisted of several substances of which four (acetone, acrylates, butyl acetate and carbon disulfide) has been previously reported to induce hyposmia or anosmia in workers. Other aetiologies were clinically excluded but a large arachnoidea cyst in the frontal part of the left temporobasal fossa with possible compression of the left entorhinal cortex. The toxic aetiology of anosmia is supported by the acute onset and the temporal relationship with occupational exposure. The silent cyst as the cause of anosmia is improbable, but it may have had some contributory role. Our case illustrates both the challenges when clinically examining patients with work-related olfactory impairment and the importance of multi-disciplinary approach to such patients.     

Impact of Elevated CO<Subscript>2</Subscript> and O<Subscript>3</Subscript> Concentrations on Biogenic Volatile Organic Compounds Emissions from <Emphasis Type="Italic">Ginkgo biloba</Emphasis>

In natural environment with ambient air, ginkgo trees emitted volatile organic compounds 0.18 μg g⁻¹ h⁻¹ in July, and 0.92 μg g⁻¹ h⁻¹ in September. Isoprene and limonene were the most abundant detected compounds. In September, α-pinene accounted for 22.5% of the total. Elevated CO₂ concentration in OTCs increased isoprene emission significantly in July (p < 0.05) and September (p < 0.05), while the total monoterpenes emission was enhanced in July and decreased in September by elevated CO₂. Exposed to elevated O₃ increased the isoprene and monoterpenes emissions in July and September, and the total volatile organic compounds emission rates were 0.48 μg g⁻¹ h⁻¹ (in July) and 2.24 μg g⁻¹ h⁻¹ (in September), respectively. The combination of elevated CO₂ and O₃ did not have any effect on biogenic volatile organic compounds emissions, except increases of isoprene and Δ3-carene in September. Foundation item: The National Natural Science Foundation of China (No. 90411019).     

Indoor air pollutants in office environments: Assessment of comfort,health, and performance

Concentrations of volatile organic compounds (VOCs) in office environments are generally too low to cause sensory irritation in the eyes and airways on the basis of estimated thresholds for sensory irritation. Furthermore, effects in the lungs, e.g. inflammatory effects, have not been substantiated at indoor relevant concentrations. Some VOCs, including formaldehyde, in combination may under certain environmental and occupational conditions result in reported sensory irritation. The odour thresholds of several VOCs are low enough to influence the perceived air quality that result in a number of acute effects from reported sensory irritation in eyes and airways and deterioration of performance. The odour perception (air quality) depends on a number of factors that may influence the odour impact. There is neither clear indication that office dust particles may cause sensory effects, even not particles spiked with glucans, aldehydes or phthalates, nor lung effects; some inflammatory effects may be observed among asthmatics. Ozone-initiated terpene reaction products may be of concern in ozone-enriched environments (≥0.1 mg/m³) and elevated limonene concentrations, partly due to the production of formaldehyde. Ambient particles may cause cardio-pulmonary effects, especially in susceptible people (e.g. elderly and sick people); even, short-term effects, e.g. from traffic emission and candle smoke may possibly have modulating and delayed effects on the heart, but otherwise adverse effects in the airways and lung functions have not been observed. Secondary organic aerosols generated in indoor ozone-initiated terpene reactions appear not to cause adverse effects in the airways; rather the gaseous products are relevant. Combined exposure to particles and ozone may evoke effects in subgroups of asthmatics.