Odor Emissions Research Articles

In vitro fermentation profiles of different soybean oligosaccharides and their effects on skatole production and cecal microbiota of broilers.

ObjectiveThe objective of this study was to investigate the in vitro fermentation profiles of different soybean oligosaccharides (SBOs) and their effects on skatole production and cecal microbiota of broilers.MethodsFive SBOs with varying main component contents were fermented using an in vitro batch incubation inoculated with broiler cecal microbiota. Gas production was recorded automatically, skatole, indole and short-chain fatty acids (SCFAs) were determined using high-performance liquid chromatography, and microbial changes were analyzed using 16S DNA gene sequencing.ResultsThe addition of SBOs increased (p<0.05) gas production, suggesting bacterial growth-stimulating activities. In addition, the concentrations of indole were significantly (p<0.05) decreased after SBO supplementation, and SBO III, with higher sucrose and stachyose contents, decreased (p<0.05) the skatole level. Our results also revealed that the fermentation of SBOs by cecal microbiota produced (p<0.05) SCFAs, which were dominated by propionic acid, butyrate acid and lactic acid compared to the control. In addition, SBO III increased (p<0.05) the abundance of Firmicutes and Subdoligranulum and decreased that of Bacteroides.ConclusionThese results suggest that SBOs with higher sucrose and stachyose contents are promising prebiotics in modulating gut microbiota and reducing odor emission in broilers.

Impacts of aluminum- and iron-based coagulants on municipal sludge anaerobic digestibility, dewaterability, and odor emission.

Although aluminum- and iron-based chemicals have been broadly used as the two most common types of coagulants for wastewater treatment, their impacts on the performance of downstream sludge management can be quite different and have not been well understood. This work reviewed and analyzed their similarities and differences in the context of the anaerobic digestion performance, dewaterability of digested sludge, and odor emission from dewatered biosolids. In short, iron-based coagulants tend to show less negative impact than aluminum-based coagulants. This can be attributed to the reduction of ferric to ferrous ions in the course of anaerobic digestion, which leads to a suite of changes in protein bioavailability, alkalinity and hydrogen sulfide levels, and in turn the sludge dewaterability and odor potential. Whether these observations still hold true in the context of thermally hydrolyzed sludge management remains to be studied. PRACTITIONER POINTS: The impacts of aluminum-/iron-based coagulant addition on municipal sludge anaerobic digestibility, dewaterability, and odor emission are reviewed. Iron-based coagulants show less negative impact on the sludge digestibility than aluminum-based coagulants. Conclusions may aid practitioners in selecting coagulants in practice and better understanding the mechanisms behind the phenomena.

Emission of Volatile Organic Compounds from Land-Applied Beef Cattle Manure as Affected by Application Method, Diet, and Soil Water Condition

HighlightsThe largest contributors to odor activity values (OAV) were heptanoic acid (23.5%), hexanoic acid (17.6%), indole (14.7%), and dimethyl disulfide (DMDS) (9.50%).Measurements of volatile organic compounds (VOC) were greater from plots where manure was surface-applied than from plots with incorporated manure.Emissions of DMDS and dimethyl trisulfide (DMTS) (0.318 and 0.074 µg m-2 min-1, respectively) were greater for plots with manure from beef cattle fed a diet containing 30% wet distillers grains with solubles (WDGS).Rainfall immediately after manure application influenced the types and amounts of VOC that were emitted.Abstract. Land application of beef cattle manure may result in the emission of volatile organic compounds (VOC). This study was conducted to evaluate the effects of diet, land application method, soil water condition, and time since manure application on VOC emissions. Manure was collected from feedlot pens where cattle were fed diets containing 0%, 10%, or 30% wet distillers grains with solubles (WDGS). The effects of manure application method (surface-applied or incorporated) and soil water condition (saturated or wet) on VOC emissions were measured over a 48 h period. Heptanoic, hexanoic, isobutyric, and isovaleric acids contributed 23.5%, 17.6%, 9.26%, and 3.39% (0.034, 0.258, 0.030, and 0.014 µg m-2 min-1), respectively, to total odor activity values (OAV). The aromatics indole and skatole contributed 14.7% and 8.84%, (0.005 and 0.0004 µg m-2 min-1), respectively, to total OAV. Dimethyl disulfide (DMDS) contributed 9.50% (0.013 µg m-2 min-1) and dimethyl trisulfide (DMTS) contributed 5.68% (0.030 µg m-2 min-1) to total OAV. Emissions of the sulfur compounds (DMDS and DMTS) were substantially greater for the 30% WDGS diet. With the exception of heptanoic acid, flux measurements were greater from the plots where manure was surface-applied than from the plots where manure was incorporated. Emissions of each VOC were greater on the first day following manure application when a saturated soil water condition was present. VOC flux values were found to rapidly decrease following manure application. Effective best management practices for reducing VOC emissions are to incorporate manure soon after application and to delay land application when there is a high probability of rainfall. Keywords: Air contaminants, Air quality, Environmental management, Land application, Manure management, Odor control, Odor emission, Odor evaluation, Volatile organic compounds, Volatile fatty acids.

Identification of odor emission sources in urban areas using machine learning-based classification models

Odor-causing substances are generated by various emission sources in urban areas. Recently, urbanization has greatly increased the density of odor emission facilities, implying the identification of odorants emission source is challenging. Identifying emission source is multifactorial, and a machine learning approach is considered useful for these complicated matters. The objectives of this study were to propose a method using machine learning-based classification models to identify odor sources in urban areas. We collected 34,539 data points regarding quantitative data of 22 compounds emitting from 11 types of facilities in urban areas (i.e., automobile industry, bio factory, wastewater treatment plant, landfill, construction site, farm industrial complex area, restaurant, gas station, roadside, park) and odor intensity of these 11 facilities. Decision tree (DT) and random forest (RF) algorithms were used as classification models for identifying odor sources with 23 variables (22 compounds + odor intensity). The DT model identified 7 out of 11 emission sources with 87.15% accuracy. The RF model identified all 11 emission sources with 99.23% accuracy. When including 6 important variables only (i.e., hydrogen sulfide, ammonia, trimethylamine, methyl mercaptan, acetaldehyde, odor intensity) in the RF model, accuracy (99.15%) was almost same with that (99.23%) obtained from all 23 variables included as variables in the model. Our findings imply that a machine learning approach can help to identify odor emission sources with high accuracy and we can save time and cost in the identification of odor emission sources by including the 6 important variables only. • Identified odor emission sources in urban areas using machine learning algorithms. • Collected 34,539 data sets of 22 substances from 11 types of emission sources. • Random forest model identified all 11 emission sources with 99.23% accuracy. • Simplified RF model with 6 important variables presented the almost same accuracy.

Assessment of Dimethyl Sulphide Odorous Emissions During Coal Extraction Process in Coal Mine Velenje

Assessment of Dimethyl Sulphide Odorous Emissions During Coal Extraction Process in Coal Mine Velenje

Community and environmental data-driven monitoring of waste management

ABSTRACT Environmental operators perform their activities in accordance with the relevant legal provisions; however, this does not mean that they operate at their technological optima using the operational information available. The possible negative effects (odor, noise, etc.) of a sub-optimal operation can be felt first and foremost by those living in the immediate vicinity of the given object. It would be important to make effective use of these citizens feedback (quickly to revealing the root causes) thus minimize negative environmental impact of operations. The solution proposed in this paper is a portal called EnviroMind, which allows citizens feedback to be recorded in an easy, immediate, and structured way via a form and on the other hand, it provides a real-time graphical odor transmission model output in a dashboard to operators. Using this portal as a monitoring system the magnitude of the odor effect could be reduced and a smaller area around the industrial object could be affected. In a landfill monitoring pilot project where this monitoring system was used the decrease in the number of indicated odor observations was 85% and the decrease in maximal distance from landfill to odor detection positions was 45%. It is proposed to use EnviroMind monitoring system for all industrial objects which have a significant odor effect on the environment, because by using it we can make the odor effect visible to operators in real time, thus, the reaction time for solving the problem can be minimized. Implications: monitoring is available online to the surrounding community, the affected population, so that quick responses and interventions are available; in the knowledge of the current technological activity carried out on the site its expected odor effect in the area can be determined, whether a protected area can be reached and what odor concentration is expected; in every 15 minutes model results to accurately track expected odor emission values; possibility of intervention, stopping or modification of the technology steps. Experience and main achievements of portal operation in a landfill monitoring pilot project from recent 3 years: the decreasing number of odor perceptions (the decrease in the number of indicated observations was 85%) and the cessation of odor effects in certain areas (and the decrease in maximal distance from landfill to odor detection positions was 45%).

EXPLORING THE EFFECT OF ORGANIC ADDITIVES ON PHYSICAL PROPERTIES OF BITUMEN

Warm additives had wide popularity in recent years due to saving in energy and lowering emissions dealt with asphalt mixture production. Warm Mix Asphalt (WMA) is produced by using foaming technology or reducing -viscosity additives of binder to enhance the rheological properties. In this study, organic-based additives (Asphaltan A and Asphaltan B) are used to investigate their effect to minimize the viscosity and lower the temperature of asphalt mixture production. Bitumen is mixed with three doses of each additive: 1, 2, and 3% of its weight. The binder viscosity was measured by rotational viscometer with and without the additives at three different temperatures. The study showed that the organic additives have a positive impact on the behavior of the binder in terms of viscosity reduction and made enhancements in terms of bitumen properties. This result could be useful in the reduction of production temperature and quantity of odour emissions.

Isolation and application of a mixotrophic sulfide-oxidizing Cohnella thermotolerans LYH-2 strain to sewage sludge composting for hydrogen sulfide odor control

To investigate the influences of sulfide oxidizing bacteria on H2S odor control in sewage sludge composting, a facultative chemolithotroph strain was isolated and identified as Cohnella thermotolerans LYH-2. Strain LYH-2 decreased the initially added sulfide by 94.6% when glucose and NH4Cl were used as the optimal energy substrates. The biotransformation of sulfide substrates followed first-order reaction kinetics, and the highest degradation rate constant (0.0537 h−1) and bacterial dry weight (0.745 g/L) were obtained at 300 mg/L of initial sulfide. The C. thermotolerans strain was inoculated as the bacterial agent into the sewage sludge and rice husk composting in forced ventilation composting reactors for 25 d; the bacterial inoculation prolonged the thermophilic period by 2 d, decreased 35.4% of H2S odor emission, and accelerated the composting process compared to the control group. The results demonstrated that C. thermotolerans inoculants effectively controlled H2S emission and promoted maturity in sewage sludge composting.

Dispersion modelling of environmental odours using hourly-resolved emission scenarios: Implications for impact assessments

Regarding air quality, odours have been repeatedly ranked as the number one reason for public complaints to authorities. The most widely used method for assessing odour impacts is dispersion modelling. However, the entire impact assessment chain is permeated with uncertainty, and the role of different sources of uncertainty is not well understood. A critical component of this chain is the emission, the focus of this work. Here we develop modelling analyses for examining the influence of variable emissions against constant emissions on the outcomes of impact assessments. The analyses are built upon six hourly-resolved emission scenarios and one time-invariant scenario applied for the fattening phase of pig production systems. All seven scenarios are configured to treat total emissions due to a mechanically ventilated shed as coming from an elevated point source with an unobstructed vertical release. A total of 378 impact maps from three sites in two countries (Austria and the U.S.) over relatively flat terrain are scrutinised. The influence and relevance of accounting for variability in odour emissions over time depend strongly on the nature of the emissions (e.g., temporal pattern, presence of stochastic and deterministic components) as well as other factors such as building downwash, odour impact criterion and stack height. Altogether, the results suggest that using hourly odour emission rates can improve the confidence in impact assessments compared with the simulations driven by constant emissions. For odour impact criteria based on high-end percentiles, the assumption of constant emissions can be more easily compromised. In contrast, lower percentiles are found to be more robust in offsetting the source emission variability. Results also indicate that the variability in odour emissions might become less of an issue for releases under the influence of downwash than those without obstacle effects. This systematic work is the largest investigation to date on the consequences of incorporating variable emissions when modelling odour impacts. Our findings demonstrate that the emission scenario used as input to dispersion models can play a central role in dictating the conclusions of odour impact assessments. • Modelling analyses were developed to produce 378 odour impact maps for the investigation. • Assuming constant emissions brings a risk of biased impact estimates. • Releases under building downwash effects were less sensitive to the source emission variability. • The ultimate influence of variable emissions hangs upon the prescribed percentile of impact criteria. • More faithful representations of time-varying emissions are needed to ameliorate odour exposure calculations.

Fallen leaves are superior to tree pruning as bulking agents in aerobic composting disposing kitchen waste

Though aerobic composting has been frequently applied to kitchen waste disposal, appropriate bulking agents are essential to acquire a promising performance. Fallen leaves and tree pruning in urbans face huge disposal demands and have great potentials as bulking agents of aerobic composting while have been seldom examined yet. This study comparably explored the performance of fallen leaves bulked and tree pruning bulked aerobic composting disposing kitchen waste. Results indicated that though both reactors were effective in degrading kitchen waste, leaf bulked composting was superior to tree pruning bulked composting in terms of longer thermophilic period and higher maximum temperature, higher organics degradation efficiency, higher humification and less odorous gas emission. Bacterial community was a driving mechanism for above results. This study shows that fallen leaves bulked aerobic composting has great potentials for kitchen waste disposal.

RHINOS: A lightweight portable electronic nose for real-time odor quantification in wastewater treatment plants

SummaryQuantification of odor emissions in wastewater treatment plants (WWTPs) is key to minimize odor impact to surrounding communities. Odor measurements in WWTPs are usually performed via either expensive and discontinuous olfactometry hydrogen sulfide detectors or via fixed electronic noses. We propose a portable lightweight electronic nose specially designed for real-time odor monitoring in WWTPs using small drones. The so-called RHINOS e-nose allows odor measurements with high spatial resolution, and its accuracy is only slightly worse than that of dynamic olfactometry. The device has been calibrated using odor samples collected in a WWTP in Spain over a period of six months and validated in the same WWTP three weeks after calibration. The promising results obtained support the suitability of the proposed instrument to identify the odor sources having the highest emissions, which may give a useful indication to the plant managers as regards odor control and abatement.

Effects of Nano-membrane on Aerobic Composting Process and Odor Emission of Livestock Manure

Aerobic composting is an important approach to treat livestock manure; however, traditional composting has some problems, such as low efficiency, or odorous pollution. In order to speed up the composting process and reduce malodorous gas emissions, this study explored the mechanism of nano-membrane for improving the efficiency of livestock manure composting. A trough aerobic composting experiment was set up to evaluate the physicochemical properties, enzyme activities, and emission of odorous gases. The results showed that covering with nano-membrane could accelerate the temperature rise; reduce the pH, organic matter(OM), and ammonia nitrogen(NH4+-N); increase electrical conductivity(EC); enhance the activities of urease, protease, cellulase, xylanase, and peroxidase; while the total cumulative emissions of NH3, H2S, and TVOC were reduced by 58%, 100%, and 61%, respectively. The correlation analysis showed that most enzyme activities were easily affected by temperature(T), EC, OM, and C/N. The emission rate of NH3 was positively correlated with T and negatively correlated with pH, and TVOC was significantly correlated with various physicochemical properties. This experiment showed that covering nano-membrane could accelerate the compost maturity and reduce the emission of odorous gases. This approach has no health risks and produces low malodorous gas, which may effectively solve the problem of pollutant emission caused by livestock manure compost fermentation, promoting the green and sustainable development of the breeding industry. In addition, it facilitates livestock manure fertilizer application, and provides technical support for the development of resource utilization of biomass waste.

H2S, MeSH, and NH3 emissions from activated sludge: An insight towards sludge characteristics and microbial mechanisms

The present study investigated the odor emission potential of activated sludge through comprehensive assessment for physicochemical properties and bacterial profile of sludge. Three types of sludges from wastewater treatment plants treating slaughterhouse (SWTP), meat processing (MWTP) and domestic wastewater (DWTP) were used based on distinct morphological features which were speculated to impact odor generation. Total element S in the SWTP sludge with relatively more disintegrated cellular debris exhibited higher level than that in the MWTP and DWTP sludge, while the emitted odorants (hydrogen sulfide and methyl mercaptan) showed the opposite patterns (i.e., the lowest level for the SWTP sludge). Nitrifying bacteria was only detected in the SWTP sludge, which was well in line with abundant nitrate in the corresponding aeration tank. Principal component analysis indicated that the potential of the odor emission from the sludge had strong correlations with dehydrogenase activity, and nitrate, which implies that these parameters may serve as referring indices for evaluating the potential of odor emission of sludge or treated product.

Health risks of odorous compounds during the whole process of municipal solid waste collection and treatment in China

The high moisture content and perishable organic waste of municipal solid waste (MSW) in China have caused the severe odor nuisance to be one of the crucial reasons for resident complaints. Understanding the environmental risks of odorous compounds lays the foundations for resolving the problems. This study collected concentration data of 86 odorous compounds in five types of MSW processing facilities/equipment which can well represent the whole process of MSW stream, including waste bins and transfer stations for collection, compost plants and anaerobic digestion plants for utilization, and landfills for final disposal. The results revealed that the occupational health risks of odorants were not fully consistent with the compound concentrations and olfactory annoyance. Higher odorous compound concentrations and more severe olfactory annoyance can be found in the MSW utilization and disposal facilities, but the occupational carcinogenic risk (2.79 × 10−5–1.12 × 10−3) was non-negligible along the whole MSW stream. Aromatic hydrocarbons and halogenated hydrocarbons were crucial contributors to the carcinogenic risk of odorous compounds emission from these facilities. Particularly for estimating the adverse impact range of MSW facilities, the carcinogenic risk was the most critical factor, implying impact distance of ∼1.5 km for MSW transfer station and ∼5 km for landfill, and even higher for the regions (such as southwest China) with lower wind speed and higher atmospheric stability. In addition to current regulations, another 5 compounds (acetaldehyde, 1,3,5-trimethylbenzene, 1,2-dichloroethane, acrolein, and benzyl chloride) that displayed high carcinogenic risks were suggested to be concerned. This study provided insights for the policymakers regarding MSW odors management, especially underscoring the importance of considering the health risks of odorous compounds.

Odor Emissions from Raw Meat of Freshly Slaughtered Cattle during Inspection.

Raw meat of Freshly Slaughtered Cattle (FSC) is characterized by a very weak odor defined as slightly sweet, which could interfere in off-odor assessment during post-mortem inspection by an official veterinarian. Despite this, no information is reported in the literature on the volatiles which are emitted by FSC meat. Thus, this research aimed to study the volatile profile of raw cattle meat at different times within 24 h of slaughtering. Volatiles were analyzed and quantified using HS-SPME-GC-MS. γ-Butyrolactone, acetoin, and to a lesser extent, acid acetic were found to be the odor-active compounds of raw meat from freshly slaughtered cattle. Quantitative differences were observed up to 24 h; since the lowest levels of the odor-active compounds were reached between two and three hours from slaughtering, this period could be the most suitable for the post-mortem inspection process.

Evaluation of Occupational Exposure Risk for Employees Working in Dynamic Olfactometry: Focus On Non-Carcinogenic Effects Correlated with Exposure to Landfill Emissions

This work aims to evaluate the non-carcinogenic health effects related to landfill odor emissions, therefore focusing on workers involved in dynamic olfactometry. Currently, the most common technique to quantify odor emissions is dynamic olfactometry, a sensorial analysis involving human assessors. During the analysis, assessors are directly exposed, at increasing concentrations, to odor samples, and thus to the hazardous pollutants contained therein. This entails the need to estimate the associated exposure risk to guarantee examiners’ safety. Therefore, this paper evaluates the exposure risk for olfactometric examiners to establish the minimum dilution level to be adopted during the analysis of landfills’ odorous samples to guarantee panelists’ safety. For this purpose, an extensive literature review regarding the pollutants emitted by landfill odor sources was conducted, comparing compounds’ chemical concentrations and threshold limit values (TLVs) to calculate the Hazard Index (HI) and thus establish a minimum dilution value. The data collected indicate that a non-negligible non-carcinogenic risk exists for all landfill emissions considered. However, from the data considered, the minimum dilution factor to be adopted is lower than the typical odor concentration observed for these sources. Therefore, the olfactometric analysis of landfill samples can be generally conducted in safe conditions.

Odour Nuisance at Municipal Waste Biogas Plants and the Effect of Feedstock Modification on the Circular Economy—A Review

The increase in the amount of municipal solid waste (MSW) generated, among other places, in households is a result of the growing population, economic development, as well as the urbanisation of areas with accompanying insufficiently effective measures to minimise waste generation. There are many methods for treating municipal waste, with the common goal of minimising environmental degradation and maximising resource recovery. Biodegradable waste, including selectively collected biowaste (BW), also plays an essential role in the concept of the circular economy (CE), which maximises the proportion of waste that can be returned to the system through organic recycling and energy recovery. Methane fermentation is a waste treatment process that is an excellent fit for the CE, both technically, economically, and environmentally. This study aims to analyse and evaluate the problem of odour nuisance in municipal waste biogas plants (MWBPs) and the impact of the feedstock (organic fraction of MSW-OFMSW and BW) on this nuisance in the context of CE assumptions. A literature review on the subject was carried out, including the results of our own studies, showing the odour nuisance and emissions from MWBPs processing both mixed MSW and selectively collected BW. The odour nuisance of MWBPs varies greatly. Odour problems should be considered regarding particular stages of the technological line. They are especially seen at the stages of waste storage, fermentation preparation, and digestate dewatering. At examined Polish MWBPs cod ranged from 4 to 78 ou/m3 for fermentation preparation and from 8 to 448 ou/m3 for digestate dewatering. The conclusions drawn from the literature review indicate both the difficulties and benefits that can be expected with the change in the operation of MWBPs because of the implementation of CE principles.

Sweet and sour: A quantitative analysis of methane emissions in contrasting Alberta, Canada, heavy oil developments

Cold heavy oil production with or without sand (CHOPS, or CHOP) are prevalent methods of oil extraction in western Canada. CHOP(S) sites account for over 40% of all reported vented methane (CH4) from oil production in Alberta, and high rates of CH4 emissions have been confirmed in independent measurement studies. In this study, we used truck-based surveys coupled with qualitative optical gas imaging (OGI) to quantify and characterize methane emission rates and sources at nearly 1350 and 940 well sites in two major CHOP(S) developments respectively in 2016 and 2018. The studies were conducted in Lloydminster, Alberta, where produced gases are sweet (i.e., <0.5% sulfur) and non-olfactory, and Peace River, Alberta, where regulations were implemented in 2017 to manage sour (i.e., >0.5% sulfur) odorous emissions (hydrogen sulfide, BTEX, etc.). Based on results from all surveys, in Peace River, 43% of measured sites were emitting CH4, compared to 37% in Lloydminster. The measured CH4 emission rates in Peace River were, however, significantly lower than in Lloydminster for both years, and had fallen from 2016 to 2018. In 2018, emissions in Lloydminster were fairly unchanged relative to previous measurements taken in 2016. OGI showed that tanks in Peace River continue to emit CH4 despite regulatory interventions and a reported venting rate of zero. The continued emissions were thus classified as “unintended venting”, which can be a consequence of the non-routine malfunction (e.g., inappropriate operator action or poor equipment design/sizing) of vapor recovery equipment. Mitigation strategies implemented in Peace River targeting olfactory compounds were beneficial in reducing and keeping CH4 emissions lower, since these gases are co-emitted, and could even be co-regulated provincially. Reciprocal to that, we might expect future air quality improvements as a consequence of the new provincial requirements to reduce CH4 emissions under amended Directives 060 and 017.

CFD modeling of different mass transfer coefficients on hydrogen sulfide emission in a flux chamber.

Hydrogen sulfide (H2S) is commonly used as an indicator for odorous gas emission monitoring in wastewater treatment plants. The H2S emission estimations can be performed using algebraic mathematical models or carrying out measurements at the source, with the dynamic flux chamber, for example. This work brings together these two methodologies in a computational fluid dynamics analysis. Fifteen liquid-phase mass transfer coefficient ([Formula: see text]) models were initially evaluated in establishing, at the liquid-gas interface in a flux chamber, an H2S emission flux based on the friction velocity field from three different inlet flows (2, 5, and 10 L min-1). Ten [Formula: see text] models were fully simulated, and the numerical results were compared with available experimental data. The higher the inlet flow, the higher the friction velocity at the interface, and the higher the H2S emission. The H2S emission was also strongly dependent on the constant coefficients of the existing [Formula: see text] models. Small variability on those coefficients generates considerable changes in emissions at the interface. Few and different models performed well in describing the available concentration data at the outlet sampling probe for different inlet flows, which shows there is still no single model capable of representing all simulated friction velocity ranges (0.005 to 0.017ms-1).

Research Progress in the Odorants and Their Emissions from Indoor Building Decoration Materials

The emission of pollutants from building decoration and furbishing materials associated with unpleasant odors is the main reason for complaints relating to poor quality indoor air. Currently, few studies have focused on the identification of odorants and the quantification of emissions from these building materials. Here, we summarize the analytical methods available for the study of indoor odorants and evaluate existing understanding of odorants from nine kinds of building materials, namely plaster board, wood-based materials, linoleum, carpets, plastics, rubber, artificial leather, paints, and adhesives. The possible odor-causing compounds emitted by these different materials and their odor threshold values are identified. Finally, suggestions are proposed for future research and control measures to minimize indoor odor pollution. Overall, olfactometry is the most important tool for odor analysis desite the non-standardized application of the technique when used in the assessment of odor emissions from building materials. In addition, there are large differences in the reported patterns of odorant emissions from building materials, although oxidized substances such as aldehydes, ketones, and acids are frequently identified in association with the aging of the materials via processes such as oxidation and ozone degradation over time.