Emissions Of Toxic Pollutants Research Articles

Sustainable Photo- and Electrochemical Transformation of White Phosphorous (P4 ) into P1 Organo-Compounds.

Elemental white phosphorous (P4 ) is a crucial feedstock for the entire phosphorus-derived chemical industry, serving as a common precursor for the ultimate preparation of high-grade monophosphorus (P1 ) fine chemicals. However, the corresponding manufacturing processes generally suffer from a deep reliance on hazardous reagents, inputs of immense energy, emissions of toxic pollutants, and the generation of substantial waste, which have negative impacts on the environment. In this context, sustainability and safety concerns provide a consistent impetus for the urgent overall improvement of phosphorus cycles. In this Concept, we present an overview of the most recent growth in photo- and electrochemical synthesis of P1 organo-compounds from P4 , with special emphasis on sustainable features. The key aspects of innovations regarding activation mode and mechanism have been comprehensively analyzed. A preliminary look at the possible future direction of development is also provided.

The potential risks and exposure of Qinling giant pandas to polycyclic aromatic hydrocarbon (PAH) pollution

Rapid industrialization and urbanization have created a substantial urban-rural gradient for various pollutants. The Qinling Mountains are highly important in terms of biodiversity, providing habitat for giant pandas, which are endemic to China and are a widely recognized symbol for conservation. Whether polycyclic aromatic hydrocarbon (PAH) exposure risks regarding in situ animal conservation zones are affected by environmental pollution or even enhanced by the mountain-trapping effect requires further research. Our group carried out a large-scale investigation on the area ranging from Xi'an to Hanzhong across the giant panda habitat in the Qinling Mountains by collecting atmosphere, soil, bamboo, and fecal samples from different sites over a two-year period. The total toxicity of atmospheric PAHs and the frequencies of soil PAHs above effect range low (ERL) values showed a decreasing trend from urban areas to the central mountains, suggesting a distance effect from the city. The proportions of total 5- and 6-ring PAHs in the atmosphere were higher in the central mountainous areas than in the urban areas, while this difference was reversed in the soil. Health risk assessments showed that the incremental lifetime carcinogenic risks (ILCR) of PAH exposure by bamboo ingestion ranged from 2.16 × 10−4 to 3.11 × 10−4, above the critical level of 10−4. Bamboo ingestion was the main driver of the PAH exposure risks. The concentration difference between bamboo and fecal samples provided a reference for the level of PAHs absorbed by the panda digestive system. Since the Qinling Mountains possess the highest density of giant pandas and provide habitats to many other endangered animal and plant species, we should not ignore the probability of health risks posed by PAHs. Monitoring the pollution level and reducing the atmospheric emissions of toxic pollutants are recommended actions. Further detailed research should also be implemented on pandas' health effects of contaminant exposure.

Field measurements of vehicle pollutant emissions in road tunnels at different altitudes

Many previous studies have focused on air quality in road tunnels, which is a major concern for ventilation design. However, few researchers have investigated the air quality in tunnels in high-altitude areas. The ambient environment in high-altitude areas featuring low oxygen content and ambient pressure can influence the vehicle pollutant emissions inside the tunnels. As a result, field measurements were carried out considering environmental parameters and gaseous pollutant concentrations in four road tunnels at different altitudes to determine exact vehicle emissions. Results show that ambient pressure is closely related to the altitude and that the oxygen content will decrease when the altitude increases due to the lower air density. The air velocity induced by the vehicle fleet is only affected by the traffic parameters and not influenced by the air density. The CO and NO emission factors in test tunnels at different altitudes were calculated according to pollutant mass balance models. We can conclude that an environment featuring low oxygen content and ambient pressure in high-altitude areas contributes to incomplete combustion of the engines and performance degradation of the catalytic converter, which leads to higher toxic pollutant emissions inside the tunnels. In this study, the CO and NO emission factors were 0.701 and 0.403 g km−1 vehicle-1 respectively at an altitude of 500 m, which then increased to 1.567 and 0.886 g km−1 vehicle-1, respectively, at an altitude of 3850 m. The NO altitude coefficient is introduced, similar to the CO altitude coefficient in the guidelines, to reflect the influence of altitude on the NO emission factor, and we can determine that the impact of altitude on the CO emission factor is greater. We hope our work will provide a reference for road tunnel ventilation design in high-altitude areas.

Study of Crude Oil Fouling from Sulfur-Containing Compounds Using High-Resolution Mass Spectrometry

With the depletion of conventional resources, heavier and more sulfur-rich crude oils come into the focus of interest. However, the utilization of such feedstocks is extremely undesirable since their high sulfur content causes corrosion fouling, catalyst poisoning, and emissions of toxic pollutants into the atmosphere. As known catalyst poisoners, sulfur-containing compounds are also suspected to play an important role in crude oil fouling, that is, the formation of undesired solid deposits. To overcome these problems, insightful knowledge on the chemical composition of the sulfur-containing compounds on a molecular level and their behavior is necessary. Here, fouling reactions of a gas condensate were simulated in the laboratory under atmospheric and inert conditions, with special focus on sulfur-containing compounds, and the resulting mixtures were analyzed by using sophisticated analytical methods such as ultrahigh-resolution mass spectrometry and electron microscopy. The results indicate that sulfur-containing compounds decompose at elevated temperatures, partly by a radical-induced mechanism. Furthermore, the resulting intermediates show a limited stability in the presence of oxygen.

Acorn germination and oak (Quercus brantii Lindl.) seedling development dramatically affected by spatial position of maternal trees from Ilam gas refinery, Iran

Air pollution from industrial areas is an environmental stress on trees that can seriously endanger the future of forests. Ancient Persian oak trees (Quercus brantii Lindl.) in the semi-arid forests of the Zagros are exposed to various environmental stresses such as air pollution from the Ilam gas refinery, which causes many challenges in forest regeneration and afforestation, thus jeopardizing forest sustainability or restoration. The aim of this study was to investigate the effect of toxic pollutants emitted from a gas refinery operation on seed germination and morphological characteristics of seedlings from maternal trees that are located at different distances (1000, 1500, 2000, 2500 and 10,000 m) and directions (east and west) from the facility. The results showed that oak seedlings grown from acorns collected at a distance of 10,000 m had the highest values in various seed germination and seedling developmental measures and morphological traits such as leaf and root mass, number and length compared to other distances of 1000, 1500, 2000 and 2500 m from the gas refinery. Highest values in seed germination, and seedling emergence and growth occurred at distances furthest from the refineries. Also, direction from the refinery significantly (p < 0.05) effected root growth, with larger seedlings occurring from acorn collected west of the refinery. The results of principal component analysis and discriminate analysis showed that, of the traits observed, various seed germination traits were most sensitive to gaseous toxic pollutants emitted from this source. Based on all studied traits, seedlings from acorns collected at 10,000 m from the facility were easily distinguished from seedlings of acorns collected at closer distances. It can be concluded that refinery toxic pollutants caused significant adverse changes in germination and seedling growth from acorns collected from oak trees located near (less than 10,000 m) to the source of air pollution. It is recommended that such pollution sources should be established far away from forest areas, and if constructed, be equipped with appropriate technologies such as flare gas recovery (FGR) to reduce emission of toxic pollutants and other emissions such as sulfur dioxide (SO2) and hydrogen sulfide (H2S) from the gas refinery. It is also strongly recommended that acorns collected for restoration measures come from maternal trees growing at a distance >10,000 m, and especially to the west of gas refineries.

Energy recovery for hybrid hydraulic excavators: flywheel-based solutions

Hybridization is an effective method to reduce fuel consumption and emissions of toxic pollutants generated by hydraulic excavators (HEs). This paper first reviews various hybrid HEs architectures with electrical, hydraulic, or flywheel-based energy recovery systems (ERSs). Flywheel-based ERS is not widely used in HEs but has achieved widespread concern in the automotive field. In light of this, the differences between HEs and automobiles are discussed to highlight the potential of flywheel-based ERSs in HEs. Then, the paper compares corresponding energy storage devices in these ERSs from many aspects. The comparison shows that flywheels display many advantages over other energy storage devices. Meanwhile, the drawbacks of flywheels are discussed in detail, indicating that the drawbacks can be offset by other advantages. The results show that the flywheel-based ERS is competitive with the electrical and hydraulic competitors for HEs. Finally, the challenges to the flywheel technology and future work are presented.

Assimilative capacity approach for air pollution control in automotive engines through magnetic field-assisted combustion of hydrocarbons.

Deterioration of air quality through the combustion of hydrocarbon fuels has been one of the global transboundary problems put before the research community since last five decades. According to the updated statistics, 79% of energy needs in India are met by fossil fuel combustion which results in the emission of toxic pollutants like carbon monoxide, oxides of nitrogen, and unburned hydrocarbons. Air quality has seriously been affected in many parts of India, and statistically, 13 out of 15 most polluted cities in the world lie in India. Magnetic field-assisted combustion has been proven as a reliable technology in internal combustion engines for enhancing the combustion of fuels and reduction of harmful emissions that are the byproducts of incomplete combustion of fuels. In the present work, the magnetic field-assisted combustion of a liquid-phase and a gas-phase fuel (gasoline and LPG) has been studied in a multicylinder automobile engine replicating on road driving conditions in a laboratory focusing on the levels of emissions in comparison with normal combustion of both the fuels. The experimental study concludes that the applied magnetic field positively influences combustion, resulting in reduced level of emission of toxic components irrespective of the phase of hydrocarbon fuels. It is also observed that the percentage reduction in emissions increases with increase in intensity of magnetization. The maximum reduction obtained for CO and UBHC emissions through this technique is 20.58% and 14.47%, respectively. The effectiveness of MFAC in countering air pollution from vehicular exhaust is also studied with respect to fuel phase and mode of operation. The effectiveness of MFAC is observed to be more in high-speed operation of the engine and decreases in the order CO > UBHC > NO. The obtained emission results have a cumulative significance as 45% of total air pollution in India is caused by combustion of hydrocarbons in automotive engines.

Cytotoxicity and Potential Pathway to Vascular Smooth Muscle Cells Induced by PM2.5 Emitted from Raw Coal Chunks and Clean Coal Combustion

Coal combustion emits a large amount of PM2.5 (particulate matters with aerodynamic diameters less than 2.5 μm) and causes adverse damages to the cardiovascular system. In this study, emissions from anthracite and bitumite were examined. Red mud (RM) acts as an additive and is mixed in coal briquettes with a content of 0-10% as a single variable to demonstrate the reduction in the PM2.5 emissions. Burnt in a regulated combustion chamber, the 10% RM-containing bitumite and anthracite briquettes showed 52.3 and 18.6% reduction in PM2.5, respectively, compared with their chunk coals. Lower cytotoxicity (in terms of oxidative stresses and inflammation factors) was observed for PM2.5 emitted from the RM-containing briquettes than those from non-RM briquettes, especially for the bitumite groups. Besides, the results of western blotting illustrated that the inhibition of NF-κB and MAPK was the potential pathway for the reduction of cytokine levels by the RM addition. The regression analyses further demonstrated that the reduction was attributed to the lower emissions of transition metals (i.e., Mn) and PAHs (i.e., acenaphthene). This pilot study provides solid evidence for the cytotoxicity to vascular smooth muscle cells induced by PM2.5 from coal combustion and potential solutions for reducing the emission of toxic pollutants from human health perspectives.

Effect of nozzle hole geometry on the operation of kapok biodiesel in a diesel engine

The strive for mitigation of toxic pollutant emissions and carbon footprints has resulted in the incursion of many renewable alternate fuels, produced from bio-derived sources. Amongst them, biodiesel, an ester of vegetable oil, has amassed immense popularity and interest for diesel engine applications. In order to operate higher blends of biodiesel in a diesel engine, engine design modification strategies are essential. This study investigates the effect of nozzle hole geometry on the characteristics of a diesel engine fueled by biodiesel. Based on this modification, the number of nozzle holes was increased from three to five and the engine characteristics were examined for the higher blend B50 (50% kapok biodiesel + 50% diesel). Modifying the nozzle hole geometry resulted in improved combustion characteristics on account of expected enhanced fuel atomization and air/fuel mixing process. The experimental study revealed an increase in peak heat release rate and in-cylinder pressure of 32.5% and 10%, respectively, for B50 when the number of nozzle holes was increased from 3 to 5 at full load condition. Furthermore, the ignition delay was shortened with a shorter burn duration (improved combustion rate) as the number of nozzle holes is increased. The modification of nozzle hole geometry offers the benefit of improved engine performance with the increase in brake thermal efficiency of 6.1% for 5 hole nozzle geometry when compared to 3 hole nozzle geometry at full load condition. Finally, from the emissions front, HC, CO, and smoke decreased with the increase in the number of nozzle holes at the penalty of increased NOX emission.

Building national emission inventories for the energy sector: Implications for life cycle assessment and nations environmental footprinting

Environmentally-extended multi-region input-output (EE-MRIO) models allow calculating environmental impacts of goods and services in a supply-chain perspective. However, current EE-MRIO databases only have limited coverage of toxic pollutant emissions. This limited coverage is caused by the fact that public emission databases currently provide a rather modest pollutant coverage, are restricted to a limited number of countries, and lack differentiation in terms of sectors. This therefore calls for alternative data sources and inventorying techniques. Using the production of heat and electricity as a case study, we investigate the usability of available process-based inventories like the ecoinvent database from the field of Life Cycle Assessment (LCA) to build national emission inventories of pollutants. We thus develop the ecoinvent-based National Energy-related Emission (ENEE) inventory, comprising a total of 231 airborne emissions and 87 waterborne emissions of pollutants from heat and electricity power plants in 140 countries over the period 1995–2014. Using the improved data sets, we demonstrate that extending the coverage of pollutants beyond the few commonly-reported ones, like greenhouse gases, has a significant influence on the quantification of other important environmental impacts such as ionizing radiation and impacts of toxic substances to freshwater ecosystems. The ENEE inventory is an important first step towards building comprehensive inventories of pollutant emissions from power and heat generation, thus enabling more complete assessments of the energy sector. It also exemplifies the gains that can be made when introducing process-based data to complement public national and sectoral data for life cycle assessments and nations environmental footprinting.

Heat transfer studies for the design and optimisation of a distillation column to separate an automotive fuel

Methylal, an automotive fuel has been noticed as a diesel alteration additive with relatively high hydrogen-to-carbon ratio. Methylal is more volatile than diesel fuel but it is used as a diesel fuel component because of its 100% miscibility with diesel fuel. An attractive feature of methylal is the reduction of particulate emissions of toxic pollutants without affecting the energy density. Unfortunately, methylal is found to form a minimum boiling azeotrope with methanol whose separation by conventional distillation is impossible. Here, we have introduced an enhanced technique of pressure swing distillation which separates methylal and methanol by exploiting its pressure sensitivity. This work has addressed the design and optimisation of a pressure swing distillation column to separate the azeotropic mixture of methylal-methanol. A novel technique of pressure swing distillation has resulted in the production of pure methylal and pure methanol. The pressure in high pressure column of pressure swing distillation process has been optimised in such a way that there is minimization of overall cost of the process with maximization of product purities. Later on, a process intensification technique of heat integration has been developed which has resulted in 55.2% savings in energy by reducing the overall load of reboiler.

Experimental prediction on the performance and propagation of ceiling jets under the influence of wall confinement

Characteristics of ceiling jets propagation are very significant for energy detecting and controlling once an undesirable energy source releasing flame and toxic pollutant emissions is erupted in a building. In many cases, the impinging ceiling jet flame will be affected by the nearby wall, especially for the energy source very close to or immediately against a wall. Four sets of experiments were conducted with energy source in open space, confined by an unbounded ceiling, confined by a wall-ceiling configuration and confined by two parallel walls (a corridor-like structure). Results show that the impinging ceiling jet-flame behaves very differently in different wall-ceiling configurations, the ceiling flame extension and the heat flux to nearby field increases dramatically with increasing confinement strength, from unbounded ceiling to narrow confined corridor-like structure. Based on the limits of flame extension, the temperature distribution under the ceiling can be divided into the near-field region within the ceiling flame and the far-field region beyond the ceiling flame. Predictive correlations of ceiling flame and temperature distribution are proposed to account for different wall-ceiling configurations. The results of this study have implications to optimize the design and arrangement of the ceiling-mounted heat and energy detection, protection and controlling systems.

Biodiesel Production from Palm Methyl Ester (PME) –Review

In the era of the increase in globalization, this led to increase in industrialization and motorization. It’s obvious that with the increase in motorization the consumptions of auto fuels had been increased since long. This may lead to a reduction of fuels (diesel &amp; petrol). Also, environmental issues have arisen from the emissions of toxic pollutants and greenhouse gases. Hence, it is necessary to look for an alternate energy source to respond this problem. To overcome this problem the replacer of fuel in CI engines had been introduced, i.e. “biodiesel”. Biodiesel is composed of fatty acid and some vegetable oils. This review paper briefly describes different biodiesel production methods, especially the production of biodiesel using palm methyl ester (PME) oil, by transesterification process. In addition, it also compares the yield of biodiesel produced form mill effluents and palm oil by-products using flask and batch reactor.

Reduction of transient soot emissions of a production Diesel engine using a fast soot sensor and closed loop control

Abstract Unfavorable combustion conditions during engine transient operation cause significantly higher emissions of toxic pollutants in comparison to static conditions. A closed loop controller could help to reduce these emissions under real driving conditions, provided the necessary measurements are available, in the diesel case mainly soot and NOx. In this paper we analyze the potential improvement of raw soot emissions using fast measurements. To this end, we consider the cumulated emissions obtained with the standard ECU setting and both with a new, fast Laser Induced Incandescence (LII) sensor and a production opacimeter. First, an emission model based on fast dynamic soot measurements is used to estimate the ideal tradeoff between soot and NOx. Then a feedback controller acting on the rail pressure is used to approximate the theoretical target. Experimental results confirm that a high reduction in soot can be achieved with a very low price in terms of NOx (-50%/+5%).

Exploring the production of bio-energy from wood biomass. Italian case study

The concerns related to the environmental impact related to energy production from fossil fuel are increasing. In this context, the substitution of fossil fuel based energy by bio-energy can be an effective solution. In this study, the production of electricity and heat in Italy in a combined heat and power plant (CHP) based on an Organic Rankine Cycle (ORC) turbine from wood based biomass both from forest and agricultural activities has been analysed considering four potential alternative scenarios to the current energy status: biomass from very short rotation forestry (VSRF) poplar and willow stands as well as residues from natural forests and from traditional poplar plantations. The evaluation has been performed by applying Life Cycle Assessment (LCA) method and an attributional cradle-to-gate approach has been followed. The expected savings of greenhouse gases emission and fossil fuels demand have been quantified, as well as derived emissions of toxic pollutants and substances responsible for acidification, eutrophication and photochemical oxidant formation.The results have been also compared with the conventional Italian scenario considering the current Italian electricity profile and heat production from natural gas. Among the different scenarios, due to the lower transport distance, the use of biomass from traditional poplar plantation residues shows the lowest impact. The biomass combustion emissions are the main hotspot for several evaluated impact categories (e.g., particulate matter formation, human toxicity). In fact, when the produced bio-energy is compared to the reference system (i.e., electricity produced under the Italian electric profile) the results do not favor bio-energy systems. The results reported in this study support the idea that forest residues would be an interesting and potential feedstock for bio-energy purposes although further research is required specifically with the aim of optimizing biomass supply distances.

Emissions of toxic pollutants from co-combustion of demolition and construction wood and household waste fuel blends

Four different types of fuel blends containing demolition and construction wood and household waste were combusted in a small-scale experimental set-up to study the effect of fuel composition on the emissions of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), chlorobenzenes (PCBzs), chlorophenols (PCPhs) and polycyclic aromatic hydrocarbons (PAHs). Two woody materials, commercial stemwood (ST) and demolition and construction wood (DC) were selected because of the differences in their persistent organic pollutants (POPs), ash and metals content. For household waste, we used a municipal solid waste (MSW) and a refuse-derived fuel (RDF) from MSW with 5–20 wt% and up to 5 wt% food waste content respectively. No clear effect on the formation of pollutants was observed with different food waste content in the fuel blends tested. Combustion of ST-based fuels was very inefficient which led to high PAH emissions (32 ± 3.8 mg/kgfuel). The use of DC clearly increased the total PCDD and PCDF emissions (71 ± 26 μg/kgfuel) and had a clear effect on the formation of toxic congeners (210 ± 87 ng WHO2005-TEQ/kgfuel). The high PCDD and PCDF emissions from DC-based fuels can be attributed to the presence of material contaminants such as small pieces of metals or plastics as well as timber treated with chromated copper arsenate preservatives and pentachlorophenol in the DC source.

Electronic Waste Management: Toxicity and Emerging Challenges in Indian Context

E-waste is posing a serious threat to the life of human being. The rate of emission of toxic pollutants from e-wastes is increasing at alarming rate. Despite the danger signals raised by various research bodies throughout the world, the governments across the globe have failed to handle this emerging issue efficiently. Where, import of used electronic products from developed nations can be cited as one of the major reasons for e-waste generation in India, handling and recycling of e-waste by unorganized recyclers in another issue. This paper attempts to throws a light on the data depicting the increase in rate of e-waste generation; it also discusses various reasons for this increase. At the end, some suggestions to overcome this issue have been given.

Assessment of emissions of greenhouse gases and air pollutants in Indonesia and impacts of national policy for elimination of kerosene use in cooking

This study presents an emission inventory (EI) for major anthropogenic sources of Indonesia in 2007 and 2010. The EI was developed using a combination of top-down and bottom-up approaches with comprehensive activity data collected at the provincial/district level to produce spatially and temporally distributed emission of toxic pollutants and greenhouse gases (GHGs). The sources were categorized into: 1) fuel combustion in power plant, 2) industry, 3) transportation, 4) residential and commercial combustion, 5) biomass open burning, and 6) non-combustion agricultural activity and waste disposal. The best estimates of the 2010 national emissions, in Gg, of toxic pollutants were: 1014 SO2; 3323 NOx; 24,849 CO; 4077 NMVOC; 1276 NH3; 2154 PM10; 1728 PM2.5; 246 BC; 718 OC; and GHGs: 540,275 CO2; 3979 CH4 and 180 N2O. During the period from 2007 to 2010, the national emissions increased by 0.7–8.8% (0.23–2.8% per year), varied with species, with the most significant changes obtained for the biomass open burning emissions. For 2010 results, the low and high emission estimates for different species were ranging from −58% to +122% of the corresponding best estimates. The largest range (high uncertainty) was for BC due to the wide range of the limitedly available emission factors. Spatially, higher emission intensity was seen in large urban areas of Java and Sumatra Islands. Temporally, dry months of August–October had higher emissions. During the first 3 years (2007–2010) of implementation, the national policy of elimination of kerosene use in cooking had successfully replaced 4.9 Tg kerosene with 2.6 Tg LPG in 30 designated provinces. The net emission reductions of different species ranged from 48 Mg (SO2) to 7.6 Tg for CO2. The global warming potential weighted emissions from the residential cooking alone, collectively for GHGs and short-lived climate pollutants in 20-yr CO2 eq., would reduce by 2%. More significant reductions in the residential combustion emissions are expected if the solid cooking fuel could be targeted in future fuel conversion programs. The benefits to human health resulted from the emission reduction of toxic pollutants from residential cooking could be substantial and should be assessed in future studies.

Reduction of Persistent Organic Pollutant Emissions during Incinerator Start-up by Using Crude Waste Cooking Oil as an Alternative Fuel

Illegal harvesting and recycling of waste cooking oil, also referred to as “gutter oil” in many countries, poses a great food safety threat. Thus, in this study the feasibility of using waste cooking oil as an auxiliary fuel in the furnace of laboratory waste incinerator was evaluated in terms of toxic pollutant emissions. Two fuel blends (W20D80 and W40D60) were blended from varying proportions of diesel fuel (D100), and waste cooking oil (W100) and their physio-chemical characteristics were subsequently determined and compared. Thermogravimetry analysis (TGA) and derivative thermogravimetry (DTG) of D100, W100, W20D80 and W40D60 showed that diesel fuel consist of more volatile short aliphatic hydrocarbons, while the waste cooking oil and its blends had more thermal stable unsaturated long chain molecules. After the de novo synthesis window of 200–400°C, 40% of waste cooking oil and 60% of diesel (W40D60) was injected at around 500–700°C, and reduced the toxicity concentrations of PCDD/Fs and PCBs by an average of 86% and 94%, respectively. This study demonstrated that, by using waste cooking oil as a fuel blend, not only can reduce the possibility of “gutter oil” being put in the food to damage the health of human beings, but also can be recycled as a kind of green fuel to reduce the emissions of persistent organic pollutants (POPs).

Captive pandas are at risk from environmental toxins

Ex situ conservation efforts are the last resort for many critically endangered species, and captive breeding centers are thought to provide a safe environment for producing individuals for eventual re‐introduction to the wild. The giant panda (Ailuropoda melanoleuca) is one of the world's most endangered animals and is a widely recognized symbol for conservation. Here, we report that captive pandas in China experience environmental and dietary exposures to high concentrations of persistent organic pollutants (polychlorinated dibenzo‐p‐dioxins, dibenzofurans, and biphenyls) and heavy metals (arsenic, cadmium, chromium, and lead). In the short term, those animals exhibiting elevated levels of such toxins should be relocated to breeding centers in less contaminated areas. Ensuring the long‐term survival of both captive and wild pandas depends in part on reducing atmospheric emissions of toxic pollutants throughout China.