Health risk assessment of polycyclic aromatic hydrocarbons and heavy metals via dietary intake of vegetables grown in the vicinity of thermal power plants

Risk assessment of trace elements in vegetables grown in river Yamuna floodplain in Delhi

Urban agriculture is common in fertile river floodplains of many developing countries. However, there is a risk of contamination in highly polluted regions. This study quantifies health risks associated with the consumption of vegetables grown in the floodplain of the urban river 'Yamuna' in the highly polluted yet data-scarce megacity Delhi, India. Six trace elements are analyzed in five kinds of vegetable samples. Soil samples from the cultivation area are also analyzed for elemental contamination. Ni, Mn, and Co are observed to be higher in leafy vegetables than others. Fruit and inflorescence vegetables are found to have higher concentrations of Cr, Pb, and Zn as compared to root vegetables. Transfer Factor indicates that Cr and Co have the highest and least mobility, respectively. Vegetable Pollution Index indicates that contamination levels follow as Cr > Ni > Pb > Zn. Higher Metal Pollution Index of leafy and inflorescence vegetables than root and fruit vegetables indicate that atmospheric deposition is the predominant source. Principal Component Analysis indicates that Pb and Cr have similar sources and patterns in accumulation. Among the analyzed vegetables, radish may pose a non-carcinogenic risk to the age group of 1-5 year. Carcinogenic risk is found to be potentially high due to Ni and Cr accumulation. Consumption of leafy vegetables was found to have relatively less risk than other vegetables due to lower Cr accumulation. Remediation of Cr and Ni in floodplain soil and regular monitoring of elemental contamination is a priority.

Polycyclic aromatic hydrocarbons in sewage-irrigated vegetables from industrial cities in Haryana, India

The majority of Indians consume a lot of vegetables because of their health advantages. High concentrations of polycyclic aromatic hydrocarbons (PAHs) in vegetables may be seriously harmful to consumers' health. The method for identifying and measuring 16 USEPA polycyclic aromatic hydrocarbons (PAHs) in samples of sewage-irrigated vegetables from three industrial cities in Haryana, India, is described in this research. Ultrasonication, liquid-liquid extraction using n-hexane as a solvent, clean-up using a Florisil column, and reversed-phase high-performance liquid chromatography with a UV detector were all included in the process. The PAHs were successfully linearized (R2 > 0.99) at various doses. Results for PAH recovery ranged from 90 to about 100%. The limit of quantification was 0.002-0.580, and the limit of detection was 0.0006-0.174 µgkg-1. Data indicated that the highest mean concentrations of ∑16 PAHs were detected in Spinach (123.36 µgkg-1), in carrot (105.09 µgkg-1), and in cucumber (63.40 µgkg-1) among leafy, underground, and fruity vegetables, respectively.

Hazardous implications of halogenated polycyclic aromatic hydrocarbons in feedstuff: Congener specificity and toxic levels in feed ingredients and feeds

Studies have shown that halogenated polycyclic aromatic hydrocarbons (HPAHs), including chlorinated (ClPAHs) and brominated PAHs (BrPAHs), could be hazardous pollutants due to their pervasive occurrence in the environment. However, their accumulation properties and toxic potentials in animal feedstuffs remain unclear. This study investigated 75 congeners of parent PAHs, ClPAHs, and BrPAHs in animal-based feed ingredients and fish and swine feeds in Japan using a GC/Orbitrap MS system. The total parent PAHs ranged from below the method detection limit ( Collapse

Key Words

• Animal feed
• HPAH derivatives
• Orbitrap GC/MS
• Risk assessment
• TEQ

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MESH Headings

• Animals
• Swine
• Polycyclic Aromatic Hydrocarbons/analysis
• Environmental Pollutants
• Gas Chromatography-Mass Spectrometry
• Japan
• Environmental Monitoring

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Grants Collapse

Affiliation(s)

Prasun Goswami National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, 305-0856, Ibaraki, Japan
Takeshi Ohura Faculty of Agriculture, Meijo University, 1-501 Shiogamaguchi, Nagoya 468-8502, Japan; Graduate School of Agriculture, Meijo University, 1-501 Shiogamaguchi, Nagoya 468-8502, Japan.
Ryotaro Suzuki Faculty of Agriculture, Meijo University, 1-501 Shiogamaguchi, Nagoya 468-8502, Japan
Natsuki Koike Graduate School of Agriculture, Meijo University, 1-501 Shiogamaguchi, Nagoya 468-8502, Japan
Mafumi Watanabe National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, 305-0856, Ibaraki, Japan
Keerthi S Guruge National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, 305-0856, Ibaraki, Japan; Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano, Osaka 598-8531, Japan.

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Review on heavy metal contaminants in freshwater fish in South India: current situation and future perspective

The primary natural resource we use in our daily lives for a variety of activities is freshwater for drinking and various developmental goals. Furthermore, the pace of human population increase worldwide is rising rapidly and has a great impact on the Earth's natural resources. Natural water quality has diminished owing to various anthropogenic activities. Water is crucial to the life cycle. On the other hand, chemical and agricultural industries pollute heavy metals. Acute and chronic diseases caused by heavy metals, such as slow metabolism and damage to the gills and epithelial layer of fish species, are divided into two categories. Pollutants can also harm liver tissues and result in ulceration as well as diseases such as fin rot, tail rot, and gill disease. The most prevalent heavy metals are As, Cr, Pb, and Hg, which are systemic toxicants that affect human health. These metals are categorized as carcinogens by the US Environmental Protection Agency and the worldwide agency for cancer research because they cause organ damage even at low exposure levels. The focus of the current study is to review various freshwater sources of heavy metal pollution.

Environmental impacts of Indian coal thermal power plants and associated human health risk to the nearby residential communities: A potential review

Worldwide, harmful emissions from coal power plants cause many illnesses contribute to premature deaths burden. Despite its high impact on human health and being a major source of toxic pollutants, coal has been considered a component of global energy for decades. Hence, this work was envisaged to understand the rising environmental and multiple health issues from coal power plants. Studies on the adverse impacts of coal power plants on the environment, including soil, surface water, groundwater and air, were critically evaluated. The health risk from exposure to different pollutants and toxic metals released from the power plant was also demonstrated. The study also highlighted the government initiatives and policies regarding coal power operation and generation. Lastly, the study focused on guiding coal power plant owners and policymakers in identifying the essential cues for the risk assessment and management. The current study found an association between environmental and human health risks due to power generation, which needs intervention from the scientific and medical fields to jointly address public concerns. It is also suggested that future research should concentrate on exposure assessment techniques by integrating source-identification and geographic information systems to assess the health effects of different contaminants from power plants and to mitigate their adverse impact.

Concentration levels and an assessment of human health risk of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in honey and pollen

Persistent organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) accumulate in the food chain due to their physical and chemical properties and adversely affect human health. For this reason, this study aimed to determine the PAH and PCB concentration levels in pollen and honey samples in urban and semi-urban areas and to evaluate the risk of cancer that may occur by ingestion in Bursa, Turkey. The average total concentrations of 14 PAH (∑₁₄PAH) compounds in pollen and honey samples were found to be 304.3 ± 192.3 ng/g (average ± standard deviation) and 650.2 ± 118.1 ng/g for the urban area, and 329.6 ± 160.6 ng/g and 464.3 ± 66.4 ng/g for the semi-urban area, respectively. Similarly, ∑₁₄PCB concentrations in pollen and honey samples were found to be 8.7 ± 3.6 ng/g and 13.0 ± 4.8 ng/g for the urban area and 7.7 ± 2.2 ng/g and 17.4 ± 4.0 ng/g for the semi-urban area, respectively. It was determined that the pollen and honey samples in both sampling areas were affected by local PCB sources. The Pearson correlation coefficient (PCC) method determined the relationship between pollen and honey samples. According to the PCC values obtained, it was observed that pollen and honey in both sampling regions exhibited a significant relationship with each other. Finally, while there was no cancer risk for PCBs due to ingestion of honey and pollen in both sampling areas, acceptable cancer risk has been calculated for PAHs.

Multidimensional Scaling of the Mineral Nutrient Status and Health Risk Assessment of Commonly Consumed Fruity Vegetables Marketed in Kyrgyzstan

Intensive production of fruits and vegetables causes heavy metal accumulation. Consumption of this kind of foodstuff is a growing concern of the modern world with the additional distress of the supply of enough foodstuffs. To contribute to this global purpose, this research aimed to find out the mineral nutrient and heavy metal concentrations of commonly consumed fruity vegetables in Kyrgyzstan. Totally, ten different fruity type vegetables were collected from five different large bazaars of Kyrgyzstan. From these, 20 samples, including washed/unwashed rinds of vegetables, were quantified in terms of their B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn contents by using inductively coupled plasma-optical emission spectrometry (ICP-OES). The concentrations of the fruity vegetables were found in the following range: B (1.392-25.816), Ca (92.814-4095.466), Cd (0.007-0.086), Cr (0.009-0.919), Cu (0.351-8.351), Fe (4.429-126.873), K (920.124-10,135.995), Mg (61.973-879.085), Mn (1.113-78.938), Na (36.132-266.475), Ni (0.039-1.215), Pb (0.081-2.906), and Zn (1.653-87.107) (mg kg^-1). It was determined that red capia pepper was the vegetable having the highest daily nutritional value according to evaluation done in our study. Taking into account of the HI values, all of the vegetables analyzed were determined to be lower than the limit value of 1 that falls into acceptable limits in terms of being safe. Peppers demonstrated the highest variation in terms of the elemental content. The high Cr content rendered hot pepper risky for consumption by both genders regarding with CR, and in terms of CR, it has been observed that nickel contents being found in vegetables including tomatoes pose a moderate risk for consumption. Quite lower risk was detected in red/Brandy-wine tomatoes, eggplants, and cucumber for both genders. As most striking result in our study, the Brandy-wine type tomato was found to be healthiest (as well as safest) and nutritious vegetable looking from the viewpoint of consumption in Kyrgyzstan.

Metal accumulation and health risk assessment in wastewater used for irrigation around the Agra Canal in Faridabad, India

Wastewater application for irrigation is a traditional and economic tool in developing nations. Yet prolonged use of wastewater for agricultural activities contributes to the accumulation of metals in both soil and vegetables. This study investigated the accumulation and contamination of vegetables with heavy metals ensuing from the application of wastewater from the Agra Canal and the associated risks posed to human health. Three sites across the Agra canal were selected for sampling (CW-1, CW-2, and CW-3), where untreated wastewater is being used to irrigate vegetables (spinach, coriander, radish, and garlic crops), for which tube-well water (TW) from a village served as the control site. Water, soil, and vegetable samples were collected from all sites. The presence in them of various metals, such as As, Pb, Cr, Mn, Cu, Zn, and Ni, was detected at all four sites. The greatest content of Mn was found in CW-1's water (7.91 mg/L), soil (633.77 mg/kg), and in spinach 368.12 (mg/kg) grown there. Significantly higher metal concentrations were observed in vegetables irrigated with wastewater than in tube-well-irrigated vegetables, with the metals ranked in accumulation as follows Mn > Zn > Ni > Cu > Cr > Pb > As. Our results also revealed that metal bioaccumulation varied enormously between foliar and non-foliar vegetables, as well as among the four sites. Daily metal intake (DMI) and health risk index (HRI) analyses suggested that children consuming contaminated vegetables are at higher risk than adults. The HRI for Mn, Ni, and Pb was above 1, which indicated significant health hazards to humans consuming the wastewater-irrigated vegetables. Moreover, the control site where tube-well water was used had an HRI below 1, signifying a negligible health risk for its consumption. Therefore, we may conclude that the extensive application of contaminated water for a longer duration would likely further increase metal accumulation in soil and vegetables that may be hazardous to living organisms.

Assessment of toxicity and potential health risk from persistent pesticides and heavy metals along the Delhi stretch of river Yamuna

The present study aims at the assessment of environmental quality of the most polluted stretch of river Yamuna along the megacity of Delhi. The study was conducted in order to examine toxicity and health hazards associated with persistent pollutants present in the fluvial ecosystem. Eighty four sediment and 56 vegetable samples from same locations were collected from the Delhi segment of river Yamuna flood plain in order to examine 20 organochlorine pesticides (OCPs) and 9 heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn). Both the organic and inorganic groups of persistent toxic substances were monitored and analysed for the extent of eco-toxicological as well as dietary health risks posed to the local population. Eco-toxicological assessment was done based on sediment quality guidelines, enrichment factor, geo-accumulation index, degree of contamination and Pollution Load Index. The dietary-risk was assessed with the help of translocation factors (TF) of these pollutants in vegetables. Carcinogenic and non-carcinogenic health risks from consumption of vegetables were also investigated. The level of concern for heavy metals was greater than that of OCPs as per the sediment quality guidelines. DDT, Cd, Pb and Zn had maximum concentrations corresponding to level 3 of concern, while Cr and Ni reached up to the highest i.e., 4th level of concern. Sediment samples were found to be enriched and contaminated significantly with Cd and moderately with Pb, as represented respectively by enrichment factors and contamination factors (CF). CF for metals lied in order Zn > Cd > CrNi > PbCu. Pollution load index was highest at the location lying on the exit point of Yamuna in Delhi. TF values greater than 1 were observed in majority of samples analysed for Ni, Cr, Cu and Zn. Spinach topped among vegetables in terms of metal contamination. Cd, Ni and Pb accumulated more in the roots, as against Mn, Zn, Cu and Cr which had higher accumulation in the shoots. Translocation factors were substantially high in vegetables for most of the OCPs, clearly indicating bioaccumulation and potential health risk to the consumers. Health risk to humans was assessed for non-carcinogenic and carcinogenic potentials from ingestion of vegetables. Hazard Quotient (HQ) > 1 due to radish (roots and leaves) and cauliflower consumption in children indicated non-carcinogenic risk. Hazard Index (HI) beyond 1 for all the vegetables (except onion leaves) confirmed substantial cumulative risk. Lifetime cancer risk (LCR) revealed moderate (spinach, radish, beet root and cauliflower) to low (all the others) levels of carcinogenic risk to humans. Cancer risks from γ-HCH, β- HCH, Hept, Hept Ep, Ald, p,p'-DDT, and Cr exposure through the food chain could be well established.

Occurrence and dietary exposure of heavy metals in marketed vegetables and fruits of Shandong Province, China

The contamination of heavy metals in vegetables and fruits is a serious threat to food safety and human health. The present study was designed to investigate the occurrence and dietary exposure of lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg) in vegetables and fruits in Shandong Province, China. Results demonstrated that the mean level of total heavy metals was 30.25 µg/kg. The most frequently found heavy metal was Cd (69.2%) with a mean value of 11.54 µg/kg. The mean exposure values of Pb, As, Cd, and Hg in vegetables were 0.052, 0.045, 0.038, and 2.40 × 10-3 µg/kg bw/day, respectively. Moreover, the calculated hazard quotient (HQ) values of mean levels for these four heavy metals were all less than 1, indicating the health risk of heavy metal exposure caused by vegetable consumption was low. This study has displayed baseline information on heavy metal contamination in vegetables and fruits, which can provide useful data support for the formulation of relevant standards and government management.

Assessment of Heavy Metal Contamination and the Probabilistic Risk via Salad Vegetable Consumption in Tabriz, Iran

Considering the importance of vegetables as a source of micronutrients and fibers in a balanced diet, there is still a concern that vegetables could also be a source of toxic heavy metal contaminants. The study aimed to determine the concentrations of lead (Pb), cadmium (Cd), arsenic (As), chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn) in the salad vegetables sold in Tabriz city, Iran, and to evaluate the probabilistic health risk assessment. The amount of toxic metals in 240 samples was evaluated by atomic absorption spectrophotometer (AAS) method. The average levels of toxic metals in the samples were found to be 1.59, 1.26, 1.42, 4.89, 13.38, 1.01, and 32.65 mg/kg for Pb, Cd, As, Cr, Cu, Ni, and Zn, respectively. According to the results, Zn and Cu had the highest concentration, whereas the lowest concentration belonged to Ni. The rank order of the toxic elements in the samples based on target hazard quotient (THQ) values was Cr > Cd > As > Pb > Cu> Zn > Ni, for both females and males. Leafy vegetables had a higher amount of total target hazard quotient (TTHQ) than tuber crops for both males and females. The carcinogenic risks of As and Pb were 0.032 and 0.03 in the females and 0.22 and 0.19 in males. According to the finding, there may be a potential risk of toxic metals, especially Cr, Cd, and As, for both females and males in Tabriz through the consumption of vegetables.

Sources evaluation, ecological and health risk assessment of potential toxic metals (PTMs) in surface soils of an industrial area, India

The present study aims to appraise the spatial distribution of potential toxic metals by using geostatistical technique and find their associated ecological and human health risks from surface soils of Durgapur industrial area, India. The results show that the mean metal concentrations are 116.03, 32.96, 154.37, 321.20, 50.08, 29.54 and 2.97 mg/kg for Pb, Cd, Cr, Fe, Cu, Ni and Hg, respectively, and majority of them is found higher than their background and world natural soil concentrations. The GIS contour map of pollution load index values clearly distinguished the studied sampling area is highly to very highly polluted by the toxic metals. Contamination factor (C_f) and geo-accumulation index (I_geo) values of studied metals show a similar sequence of Hg > Cd > Pb > Fe > Cr > Ni > Cu. Calculated enrichment factor (EF) value for Hg (13.29), Cd (5.26) and Pb (1.11) in studied soils was found significantly higher, which suggests that their primary sources are higher industrial activities in the studied area. Computation of potential ecological risk index reveals that the entire study area is under high risk level (1941.60-3367.23), in which Cd (588.52) and Hg (1979.26) possess the maximum ecological risk factor in all the sampling sites. The results of correlation analysis, principle component analysis and cluster analysis explore that industrial discharges, atmospheric disposition and waste disposal are the major sources of soil metal pollution in the studied region. Human health hazard indices are lower than 1 for all metals, indicating low non-carcinogenic risks to children and adults. Carcinogenic risk assessment reveals the existence of cancer risk of Cd (5.5E-03), Cr (8.6E-04) and Ni (3.0E-04) to child and Cd (8.2E-04) and Cr (1.3E-04) to adults in Durgapur.

PET-microplastics as a vector for heavy metals in a simulated plant rhizosphere zone

Although microplastics (MPs) are ubiquitous contaminants in different ecosystems, their interactions with other pollutants including heavy metals remain relatively unknown. Wheat is an important grain that makes the basis of human food in many parts of the world. Thus, pollutants that affect its production are important subjects of study. This research focuses on the possible effects of the transport of the adsorbed heavy metals onto MPs to the roots of growing wheat. The adsorption of three heavy metals (Pb, Cd, and Zn) onto PET particles was examined. Pb and Cd were selected because they are known to be toxic, while Zn is an essential nutrient for plants. Adsorption experiments were performed using 1 g of PET-MP particles in 20 ml of five different concentrations of each individual element (Pb, Cd, and Zn) (denoted as S-elements). To investigate the antagonistic and synergistic effects of these elements on each other, they were studied collectively with all 3 elements present (denoted as C-elements). Desorption experiments were then performed for three scenarios in which the wheat rhizosphere zone was simulated. Generally, the concentration of the investigated heavy metals adsorption on polyethylene terephthalate (PET) decreased in the order: S-Cd > S-Zn > S-Pb and C-Zn > T-Cd > C-Pb. PET particles exposed to Zn, Cd, and Pb solution adsorbed from 7.2 to 8.5%, 5.3 to 9.8%, and 29.8 to 68.5% of the initial heavy metals concentration, respectively. 11.3 to 15.2%, 12.5 to 23.35%, and 5.5 to 33.6% of the initially adsorbed Zn, Cd, and Pb were desorbed in the wheat rhizosphere zone in the three defined scenarios, respectively. The results show that PET particles can act as a vector in transferring heavy metals to the rhizosphere zone.

Determination of cadmium and lead in tomato (Solanum lycopersicum) and lettuce (Lactuca sativa) consumed in Quito, Ecuador

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Cadmium content was lower than 0.100 mg/kg (tomato) and 0.200 mg/kg (lettuce).

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Lead content above or close to 0.100 mg/kg was found in 25 % of tomato samples.

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Organic products had similar lead and cadmium content as nonorganic ones.

Vegetables are one of the most important components in the human diet, but despite their multiple nutritional components, studies have demonstrated the presence of trace metals in their edible parts. In Ecuador, two of the most consumed crops are tomato (Solanum lycopersicum) and lettuce (Lactuca sativa). The importance of these two crops in the Ecuadorian diet, especially in large and touristic locations like the Metropolitan District of Quito, implies food safety-related concerns for locals and visitors. However, no previous studies have quantified the cadmium and lead levels in these two vegetables using samples from Quito markets. Thus, the aim of this study was to determine the cadmium and lead content in both tomato and lettuce products from main nonorganic and organic markets in Quito using a graphite furnace atomic absorption spectrophotometer. The results showed that the cadmium levels were lower than 0.058 in tomatoes and 0.034 mg/kg in lettuce, which are under the respective threshold values (0.100 and 0.200 mg/kg). Regarding lead, levels lower than 0.066 mg/kg were detected in lettuce, which did not exceed the CXS 193–1995 threshold value, while levels in tomatoes were near or exceeded the threshold value (0.100 mg/kg) from four markets (0.209, 0.162, 0.110, 0.099 mg/kg), suggesting a possible risk from tomato consumption. In addition, most vegetables marketed as organic had higher metal content than those coming from nonorganic markets. Based on these results, local health and commercial control authorities should monitor contaminants in food products sold in Quito and other places in Ecuador to ensure their safety.

Heavy Metals and PAHs in Meat, Milk, and Seafood From Augusta Area (Southern Italy): Contamination Levels, Dietary Intake, and Human Exposure Assessment

Heavy metals and PAHs were measured in animal foodstuffs from Augusta-Melilli-Priolo area in order to evaluate the potential human health risk associated to their consumption. All heavy metals were detected in seafood products while most of them were 1 for baby, children and teenagers, indicating a non-carcinogenic risk for these age categories by seafood ingestion. The CRAs overcame 1*10-5 for almost age categories (except "baby") and for elderly, by seafood and beef ingestions respectively. Moreover, the MOE for PAHs showed a certain cancer risk for "baby" related to cow milk ingestion.

Physiological and biochemical responses of Amaranthus cruentus to polycyclic aromatic hydrocarbon pollution caused by thermal power units

Pollution due to release of polycyclic aromatic hydrocarbons from thermal power plants is a major global issue as the same is highly toxic and carcinogenic. The current research aims to investigate the responses of a dietary plant Amaranthus cruentus towards PAH pollution. For the said purpose, the plant was collected from agricultural land in close vicinity to thermal power units and the effects of PAH pollution on its chlorophyll and various nutraceutical content was evaluated. Oxidative stress biomarkers and antioxidant defense enzymes status and PAH accumulation was quantified as well. Real-time evidence of cell death, depletion of nutraceutical resources, and stomata configuration was generated through various histochemical studies and SEM analysis. Results indicated significant decline of chlorophyll a to the extent of 77% when compared to control. Oxidative stress markers, namely, superoxide radical, H₂O₂, and hydroxyl radical in pollution exposed plants were 12.7, 2.2, and 2.4 times respectively higher over the control which eventually resulted in 35% more cell death for the pollution exposed group. Total phenolics and flavonoids showed a decline of 57.6% and 41.3% respectively in the group exposed to PAH pollution. Similar decreasing trend was also observed for ascorbic acid, α-tocopherol, β-carotene, total proteins, and carbohydrate contents as well. PAH-induced stress also resulted in complete imbalance in the redox homeostasis of the plant which was evident from increase in super oxide dismutase, catalase, and peroxidase antioxidant enzymes by more than 2-fold when compared to control. PAH accumulation in sample group was 10-20 times more when compared to control. Proteomic analysis also indicated upregulation of some proteins related to stress situation. Results are evident of the fact that severe depletion of nutraceutical resources of dietary plants can take place if subjected to oxidative stress arising from PAH pollution.

Distribution and health risk assessment of potentially toxic elements in soils around coal industrial areas: A global meta-analysis

Coal production and utilization are recognized as two principal sources of potentially toxic elements in the environment. Here the published literature (2008-2018) was searched to collect data on As, Ni, Cd, Cu, Cr, Hg, Pb and Zn concentrations in soils near different types of coal industrial areas such as coal mines, thermal power plants, coal chemical plants, coal mining cities and coal waster piles. The contamination levels of soils and associated health risks were assessed using global reference materials and multiple contamination indices. The results revealed that average concentrations of potentially toxic elements varied widely, yet most of them exceeded global averages in background soils and upper continental crust concentrations. Spatial distribution analysis suggested the concentrations of potentially toxic elements varied according to coalification and combustion conditions. Higher concentrations were found in Southeast Asia, South Europe, and North Africa compared with other regions. Assessment of the geoaccumulation index revealed that contamination levels of Cd and Hg were higher than those of other elements. In particular, Ni, Cd, Zn, and Hg were most likely to accumulate in soils near coal mining areas, while Cd and Hg tended to accumulate near coal chemical plants. Regarding non-carcinogenic risks, oral ingestion was the major pathway of exposure to potentially toxic elements in coal industry-associated soils, followed by dermal contact and inhalation. Tolerable non-carcinogenic risk of potentially toxic elements and relatively high carcinogenic risks of As were observed. Children were most vulnerable to non-carcinogenic risks, while the carcinogenic risks estimated for adult and children populations were similar. Accordingly, As should be designated as top candidates for priority control to protect human health in the vicinity of coal industry-associated areas. This study provides timely information for developing control and management strategies to reduce soil contamination by potentially toxic elements in different types of coal industrial areas.

Association between exposure to polycyclic aromatic hydrocarbons and attention deficit hyperactivity disorder in children: a systematic review and meta-analysis

Some studies have shown that exposure to polycyclic aromatic hydrocarbons (PAHs) is a dangerous factor for attention deficit hyperactivity disorder (ADHD). This systematic review and meta-analysis aimed to clarify this relationship, and to collect and analyze all the relevant evidences in published reports of epidemiologic studies. PubMed, Science Direct, Web of Science, Scopus, and Google Scholar databases were searched through September 31, 2018. The study quality was evaluated using the Newcastle-Ottawa Scale. Moreover, fixed- and random-effect models were used. The data in this meta-analysis were presented as adjusted odds ratio (AOR). From 959 articles, six articles were included in the systematic review, and for meta-analysis, one study (that was not AOR) was excluded. The participants included in the studies were 2799 with the age range of 5-15 years old, and 93.6% were living in America. Four of the studies were placed in one group, due to having a common author (Perera). Moreover, a significant association was found between PAH exposure and ADHD in these studies (odds ratio = 2.57, 95% CI = 1.75-3.78); however, in all studies, there was no significant association between PAH exposure and ADHD for children (overall odds ratio = 1.99, 95% CI = 0.96-4.11) with low heterogeneity (I² = 28.73%; P value < 0.001). This study provided a systematic review and meta-analytic evidence for the association between PAH exposure and ADHD by a small number of studies. Further research study can be conducted in various countries. Graphical Abstract.

Assessment of Foliar Uptake and Accumulation of Airborne Polyaromatic Hydrocarbons Under Laboratory Conditions

Urban horticulture and community gardening have become more and more popular in the past years, however, the risk of bioaccumulation of atmospheric polyaromatic hydrocarbons (PAHs) in vegetables grown in polluted areas cannot be neglected. In our study, the No. 227 OECD GUIDELINE FOR THE TESTING OF CHEMICALS: Terrestrial Plant Test: Vegetative Vigour Test was followed to assess foliar uptake of PAHs from aqueous extract of an urban aerosol. Using lettuce (Lactuca sativa) as a test organism, significant accumulation was experienced. The highest bioconcentration factors (BCFs) were experienced for naphthalene and for anthracene, pyrene and fluoranthene showed the lowest bioaccumulation potential. BCF of each PAH showed strong correlation with molecular weight. The standard protocol defined by the Guideline made it possible to assess bioaccumulation pattern under controlled laboratory conditions.

In vitro lead tolerance and accumulation in three Chrysanthemum cultivars for phytoremediation purposes with ornamental plants

The use of ornamental plants for the phytoremediation of potentially toxic elements in polluted soils is an interesting task. It makes possible to combine environmental restoration, re-use of land, and the production of goods and services of economic interest. In this work, in vitro experiments using three cultivars of Chrysanthemum (Asteraceae) were carried out with 0, 300, 600, 900, and 1500 mg/kg of lead concentrations for a period of 12 weeks. The objective was to obtain data about their lead tolerance and bioaccumulation capacity in order to know their potential as phytoremediators in a densely populated Caribbean area of the Dominican Republic with a high concentration of lead in soils. The variations in biomass, root growth as well as accumulation of this element in the plants were measured. The results suggest that the three cultivars have a good potential for phytoextraction at moderate pollution levels, as they showed a good bioaccumulation of lead, which had mild effects on their biomass production and root elongation. Additional studies should be carried out to assess their effectiveness as phytoextractors under field conditions, as well as other alternative uses that could generate esthetic, environmental, and/or economic benefits for tropical areas contaminated by Pb.

Concentrations and distributions of polycyclic aromatic hydrocarbon in vegetables and animal-based foods before and after grilling: Implication for human exposure

The effects of grilling on health risks posed by polycyclic aromatic hydrocarbons (PAHs) in food remain poorly understood. The changes of concentrations, distributions, and risks of PAHs in vegetables and animal-based foods before and after grilling were investigated in this study. The sum of 16 (∑₁₆) PAH concentrations in grilled vegetables and grilled animal-based foods were 60.4-1936 and 69.1-4668 ng/g, respectively. Grilling markedly increased the ∑₁₆ PAH concentrations in most foods analyzed. Grilling clearly increased the low-molecular-weight PAH contributions to the ∑₁₆ PAH concentrations in vegetables but increased the heavier PAH contributions to the ∑₁₆ PAH concentrations in some animal-based foods. With the grilling, the total benzo[a]pyrene-equivalent concentrations of the 16 PAHs in Chinese chives and enoki mushrooms and most animal-based foods were improved significantly. Source assessments indicated that environmental sources contributed PAHs to the raw foods and high-temperature pyrolysis during grilling contributed large proportions of the PAHs in the grilled foods. The carcinogenic risks to humans from the exposure of PAHs in vegetables and animal-based foods were estimated. Grilling increased the total risks of PAHs in vegetables and animal-based foods by factors of 3.12 and 5.49, respectively. Total risks of PAHs in the 11 foods were 3.43 times higher when the foods were grilled than when raw. The results suggested that the negative effects of grilling on human health should be of great concern.

Colonization of polycyclic aromatic hydrocarbon-degrading bacteria on roots reduces the risk of PAH contamination in vegetables

This is a primary investigation on the mitigation of polycyclic aromatic hydrocarbon (phenanthrene as a model PAH) contamination in vegetables including water spinach (Ipomoea aquatica Forsk), pakchoi (Brassica campestris) and Chinese cabbage (Brassica chinensis) using a gfp-labeled PAH-degrading bacterium (RS1-gfp). Effective root colonization led to dense RS1-gfp populations inhabiting the rhizosphere and endosphere of the vegetables, which subsequently led to a reduction in phenanthrene accumulation and risk in vegetables. When compared with the controls without RS1-gfp, the amount of phenanthrene accumulation due to strain RS1-gfp colonization reduced by up to ~93.7% in roots and ~75.2% in shoots of vegetables, respectively. The estimated incremental lifetime cancer risk (ILCR) for adults due to phenanthrene in vegetables was reduced by 24.6%-48% through RS1-gfp inoculation. The proposed method was developed to circumvent the risk of phenanthrene contamination in vegetables by inoculating PAH-degrading bacteria. The findings provide an in-depth understanding of PAH detoxification in agricultural plants grown on contaminated sites by exploiting bacteria like RS1-gfp, which portray both rhizo- and endophytic lifestyles.

Dietary Exposure Assessment of Potentially Toxic Trace Elements in Fruits and Vegetables Sold in Town of Kapan, Armenia

Fruits and vegetables grown under the impact of Armenia's mining industry are widely sold in markets of adjacent towns. As the share of fruits and vegetables in Armenians' diet is significant, the present study aims to assess the dietary exposure of potentially toxic trace elements through the intake of fruits and vegetables sold in Kapan town, located in the biggest mining region of Armenia. The concentrations of Cu, Mo, Ni, Cr, Pb, Zn, Hg, As, and Cd in 15 types of fruits and vegetables were determined. Non-carcinogenic and carcinogenic risks were assessed. Although the estimated daily intakes of trace elements for each studied food item did not exceed health-based guidelines values, in case of the combined consumption of fruits and vegetables estimated cumulative daily intakes exceeded reference doses for Cu and Mo. Moreover, carcinogenic risk for the majority of fruits and vegetables exceeded the EPA recommended risk level of 10^-6, indicating adverse health effect to local population. The outcomes of this study can serve as a basis for further research that will consider many other exposure pathways (i.e., inhalation or dermal pathways) in order to ensure the safety of the residents living under the impact of mining industry.

Human health risk exposure with respect to particulate-bound polycyclic aromatic hydrocarbons at mine fire-affected coal mining complex

Particulate-bound poly-aromatic hydrocarbons (PAHs) are of great concern due to their mutagenicity and carcinogenicity effect on human health. In this context, identification, quantification and inhalation cancer risk (ICR) assessment due to PM₁₀- and PM_2.5-bound PAHs has been carried out at six monitoring stations in a critically polluted Jharia coalfield/Dhanbad City. Identification of pollution sources at study area has been performed by using PCA statistical methods. Air quality index (AQI) and air quality health index (AQHI) were calculated based on the concentration levels of PM₁₀. Location-wise direct comparison between AQI, AQHI and ICR was performed to analyse the risk levels. Consequently, maximum concentration levels of particulate (PM_2.5 and PM₁₀)-bound total PAHs (400 and 482 ng/m³) were recorded at the monitoring station Lodna Thana, followed by Bank More and Sijua Stadium, respectively. It was also observed that mine fire-affected station Lodna Thana was exaggerated with presence of PAHs due to wood and open coal burning activities. Moreover, about 1000 and 889 cases of inhalation cancer risk were estimated due to direct exposure of PM₁₀- and PM_2.5-bound PAHs in the study area, respectively. Active mine fire-affected station Lodna Thana was recorded with maximum probability of lung tumour due to inhalation cancer risk. This study has reported higher AQHI at station Dugdha Basti, Lodna Thana and Bank More, which results increased number of tumours due to ICR. This result concludes that Jharia coalfield/Dhanbad City are not only critically polluted area but it is also an inhalation cancer prone area due to direct exposure of active mine fire.

Genotoxicity of the vegetables juice grown in garden built on the tailings coal deposits

The aim of the present study was to evaluate the genotoxic effect of lettuce (Lactuca sativa L.), beet (Beta vulgaris L.), broccoli (Brassica oleracea var. italica), and kale (Brassica oleracea var. acephala) grown in vegetable garden built on the deposits of coal tailings. For this, we used 72 healthy male Swiss albino mice that received juice from the vegetables in an acute or chronic treatment. Using comet assay, we determined that acute administration of the juices of all vegetables from the coal-mining area was genotoxic, and increased the DNA damage in the blood, liver, and cerebral cortex of mice. Therefore, the present data suggest that intake of vegetables cultivated over coal waste results in an increase in DNA damage in some organs; this situation may pose a risk to health.

Health risk from dietary exposure to polycyclic aromatic hydrocarbons (PAHs) in a typical high cancer incidence area in southwest China

This study was designed to test whether the dietary intake of polycyclic aromatic hydrocarbons (PAHs) is a potential exposure source relating to the high cancer incidence area in southwest China. Duplicate plate method was used to collect food samples in rural and urban sites in the region. Questionnaire surveys were conducted among 300 local residents to obtain their dietary habits and 50 subjects were chosen to collect the samples. The 16 priority PAHs (PAH₁₆) in composite food samples for each individual subject were measured, and non-carcinogenic and carcinogenic risks were analyzed based on the results of Monte Carlo method. The average concentration of the PAH₁₆ in food samples was 12.04 ± 8.52 ng g^-1. The life time average daily benzo(a)pyrene equivalent (BaP_eq) exposure dose was 6.07 × 10^-6 mg kg^-1 day^-1. Although non-carcinogenic risk was found to be within a controllable range, the average incremental lifetime cancer risk (ILCR) was 3.7 × 10^-5 for rural subjects and 6.1 × 10^-5 for urban subjects, which is comparable with other regions in China. The serious risk level of 10^-4 was exceeded by 10.7% of urban residents and 2.1% of rural residents. This study implies that dietary exposure to PAHs is a potential exposure source to the high cancer in the region, and further cancer risk control strategies need to be formulated.

Evaluation of selected polychlorinated biphenyls (PCBs) congeners and dichlorodiphenyltrichloroethane (DDT) in fresh root and leafy vegetables using GC-MS

Persistent organic pollutants (POPs) are dangerous and toxic pollutants that may cause adverse effects on human and animal health, including death. POPs such as polychlorinated biphenyls (PCBs) and pesticides are subtly released into the environment from industrial and agricultural use. Global circulation is due to their trans-boundary transport capacity, contingent on aerodynamic and hydrological properties. Plants have capacity to take-up POPs, and these bio-magnify along heterotrophic transfer pathways. In this study, levels of selected 6-PCB congeners and 3- DDTs in some leaf and root vegetables were investigated. Leaf and root vegetables were collected from different horticultural farms areas in Cape Town. The 6-PCBs and 3-DDTs were recovered from the samples using solid phase extraction(SPE), followed by GC-MS analysis. The ΣPCBs and ΣDDT (on-whole basis), were ranged: 90.9–234 ng/g and 38.9–66.1 ng/g respectively. The 3-PCBs and 6-DDTs levels were slightly higher in leaf vegetables compared to root vegetables. The detection of PCBs and DDTs in the vegetables suggest the probable use of PCBs containing pesticides. Although the observed concentrations were below the WHO maximum residue limits, consumption of such contaminated leaf and root vegetables portend a health risk.

Accumulation characteristics and potential risk of PAHs in vegetable system grow in home garden under straw burning condition in Jilin, Northeast China

The accumulation characteristics and potential risk posed by polycyclic aromatic hydrocarbons (PAHs) in soils and vegetables grown in the home garden and agricultural field were investigated in this research. The average concentrations of 16 PAHs in soils and vegetables in the home garden were 508.9 ng/g and 197.3 ng/g, respectively, and in agricultural fields were 589.9 ng/g and 171.3 ng/g, respectively. The 16 PAHs concentrations of vegetables in the home garden were a little higher than in agricultural field. The most abundant PAHs in soils and vegetables was Phe, followed by Fla and Pyr in our study area. The concentrations of low-molecular-weight PAHs (L-PAHs) were higher in vegetables as compared to higher molecular weight 4-6 ring PAHs (H-PAHs). The results of plant concentration factor (PCF) indicated that L-PAHs have greater mobility in our research. Based on the results of PAH ratios, the main sources of the PAHs in soils were determined to be the combustion of biomass, coal, and petroleum. The total values of incremental lifetime cancer risk (ILCR) for males and females induced by soils and vegetables in home garden and agricultural field were all about 10^-7 and 10^-10. All the ILCRs value were lower than the baseline value, indicated that the carcinogenic risk for the soils and vegetables contaminated with PAHs in our study area for the residents was negligible.

Characterization of polycyclic aromatic hydrocarbons (PAHs) in vegetables near industrial areas of Shanghai, China: Sources, exposure, and cancer risk

Dietary consumption of contaminated vegetables may contribute to polycyclic aromatic hydrocarbon (PAH) exposure in humans; however, this exposure pathway has not been examined thoroughly. This study aims to characterize the concentrations of PAHs in six types of vegetables grown near industrial facilities in Shanghai, China. We analyzed 16 individual PAHs on the US EPA priority list, and the total concentration in vegetables ranged from 65.7 to 458.0 ng g^-1 in the following order: leafy vegetables (romaine lettuce, Chinese cabbage and Shanghai green cabbage) > stem vegetables (lettuce) > seed and pod vegetables (broad bean) > rhizome vegetables (daikon). Vegetable species, wind direction, and local anthropogenic emissions were determinants of PAH concentrations in the edible part of the vegetable. Using isomer ratios and principal component analysis, PAHs in the vegetables were determined to be mainly from coal and wood combustion. The sources of PAHs in the six types of vegetables varied. Daily ingestion of PAHs due to dietary consumption of these vegetables ranged from 0.71 to 14.06 ng d^-1 kg^-1, with contributions from Chinese cabbage > broad bean > romaine > Shanghai green cabbage > lettuce > daikon. The daily intake doses adjusted by body weight in children were higher than those in teenagers and adults. Moreover, in adults, higher concentrations of PAHs were found in females than in males. For individuals of different age and gender, the incremental lifetime cancer risks (ILCRs) from consuming these six vegetables ranged from 4.47 × 10^-7 to 6.39 × 10^-5. Most were higher than the acceptable risk level of 1 × 10^-6. Our findings demonstrate that planting vegetables near industrial facilities may pose potential cancer risks to those who consume the vegetables.

PAHs in Indian diet: Assessing the cancer risk

Food products such as bread, biscuits, tea, coffee, oils, chocolates, grapes, pepper and fishes belonging to different categories represent a significant part of everyday diet in India and other countries having variable cooking techniques. In this study, we evaluated cancer risks of long term exposure to polycyclic aromatic hydrocarbons (PAHs) through consumption of these products for eight societal groups in India. Total concentrations of PAHs in these products from India ranged from 0.18 to 61967 μg kg^-1 and the cancer risk values for the eight sections of Indian population ranged between 7.63E-10 to 5.05E+00, indicating product specific distribution of risk from non-significant to significant levels. Cereals, vegetables and decoctions contributed majorly to cancer risk and the most susceptible group identified was children. The spread of risk estimates followed Burr and Exponential distributions. To the best of our knowledge, this is the first study to develop information on the health risk faced by Indian population through dietary PAHs.

In-situ examination of graphene and graphene oxide impact on the depuration of phenanthrene and fluoranthene adsorbed onto spinach (Spinacia oleracea L.) leaf surfaces

To further assess the human being's exposure to polycyclic aromatic hydrocarbons (PAHs) through the dietary pathway, understanding the partitioning of these chemicals co-existed with nanomaterials in edible vegetable systems deserves specific consideration. In this study, the fiber-optic fluorimetry was applied to in situ examine the effects of graphene (GNS) and graphene oxide (GO) nanosheets on the quantification and depuration of three-ringed phenanthrene (Phe) and four-ringed fluoranthene (Fla) adsorbed individually onto the living spinach (Spinacia oleracea L.) surfaces. When the GNS and GO dosages separately increased to the maximum values: a respective red-shift of 4-5 nm and blue-shift of 2-3 nm occurred for the optimal detection emission wavelengths (λ_em) of the two PAHs, indicating that individual GNS and GO resulted in different changes to the epicuticular wax (ECW) polarity; GNS-inducing fluorescence quenching for the PAHs was about two times greater than GO, owing to the stronger π-π interactions between PAH molecules and GNS relative to GO; the volatilization coefficients (k_C1) were reduced by 31.1% versus 26.7% for Phe, and 51.6% versus 34.4% for Fla, mainly via providing an additional adsorbent and promoting the accessibility of the leaf cuticle; respective photolysis coefficients (k_P2) of Phe and Fla decreased by 42.9% and 50.0% with GNS, primarily owing to the enhancement of the ECW light-adsorption capacity, but increased by 33.3% and 40.0% with GO due to its photocatalytic activities; overall, total depuration coefficients (k_T1, k_T2) of the two PAHs decreased by 11.1-55.6%. These findings demonstrate that GNS and GO significantly alter the depuration behavior of PAHs in vegetable systems, potentially posing a threat to the safety of edible vegetables.

Elucidating the urban levels, sources and health risks of polycyclic aromatic hydrocarbons (PAHs) in Pakistan: Implications for changing energy demand

Due to the severe fuel crisis in terms of natural gas, a paradigm shift in fuel combustion (diesel, gasoline, and biomass) may increase the atmospheric emissions and associated health risks in Pakistan. Present study was aimed to investigate the concentration of fugitive PAHs in the environment (outdoor and indoor settings), associated probabilistic health risk assessment in the exposed population, and possible linkage between fuel consumption patterns and PAHs emissions in twin cities (Rawalpindi and Islamabad) of Pakistan. Results showed that the mean PAHs concentrations (air: 2390pgm^-3; dust: 167ngg^-1) in the indoor environment were higher than that of the outdoor environment (air: 2132pgm^-3; dust: 90.0ngg^-1). Further, the source apportionment PCA-MLR receptor model identified diesel and gasoline combustion as the primary PAHs sources in the urban and sub-urban settings. Estimated life cancer risk (LCR) potential via inhalation to indoor PAHs was higher with a probability of 2.0 cases per 10,000 inhabitants as compared to outdoor exposure. Incremental lifetime cancer risk (ILCR) model from exposure to dust bound PAHs showed risk in the order of ingestion>dermal>inhalation for various exposure pathways. Likewise, estimated daily intake (EDI) model reflects that PAHs in surface dust enter into the human body mainly through the respiratory system because EDI for breathing was reported higher than that of oral intake. Therefore, adoption of sustainable fuels is recommended to meet the energy requirements and to reduce PAHs emissions and related health risks in the twin cities of Pakistan.

Halogenated and parent polycyclic aromatic hydrocarbons in vegetables: Levels, dietary intakes, and health risk assessments

Halogenated polycyclic aromatic hydrocarbons (HPAHs) are attracting increasing concern because of their greater toxicity than their corresponding parent PAHs. However, human exposure to HPAHs via food consumption is not fully understood. In this study, daily intake via vegetable ingestion of 11 HPAHs and 16 PAHs and subsequent cancer risk were assessed for population in Beijing. A total of 80 vegetable samples were purchased from markets, including five leafy vegetables and three root vegetables. The concentrations of total HPAHs (∑HPAHs) were 0.357-0.874ng/g in all vegetables, lower than that of total PAHs (∑PAHs, 10.6-47.4ng/g). ∑HPAHs and ∑PAHs concentrations in leafy vegetables were higher than those in root vegetables, suggesting that the atmospheric deposition might be the dominant source of PAHs and HPAHs in leafy vegetables. Among the HPAH congeners, 2-BrFle and 9-ClFle were the predominant compounds and frequently detected in the vegetable samples. HPAHs and PAHs were also found in certificated vegetables at the concentrations of 0.466-0.751ng/g and 10.6-38.9ng/g, respectively, which were lower than those in non-certificated vegetables except for spinach. For leafy vegetables from local farms, the ∑PAHs and ∑HPAHs levels in the rape and Chinese cabbage samples significantly decreased with increasing the distance away from the incineration plant. The incremental lifetime cancer risks of HPAHs were below the acceptable risk level (10^-6), suggesting that there might be little or no risk to consumers from these compounds in vegetables. For all population groups, children were the most sensitive population to PAHs and HPAHs, and their health issues should be paid more attention.

Probabilistic estimates of heterocyclic amines and polycyclic aromatic hydrocarbons concentrations in meats and breads applicable to exposure assessments

Random effect meta-regressions were constructed to estimate concentrations of two heterocyclic amines (HCA) and eight polycyclic aromatic hydrocarbons (PAH) in meat and breads. Eighteen HCA studies and nine PAH studies of food concentration were assembled. Concentration was computed for beef, poultry, pork, and seafood, and bread. Fixed effect predictors included cooking time, form of the food, cooking method, interaction between form and cooking method, temperature at which the food was cooked, fuel of the flame source, percentage of fat, and other elements. Meat type was significant to all HCAs but only three of the PAHs. Cooking method or an interaction between cooking method and food form was significant in all the overall models for each compound, and 80% of models created for stratifications of the data based on meat type. Improvement on compilations such as the Computerized Heterocyclic Amines Resource for Research in Epidemiology of Disease (CHARRED) database comes from inclusion of additional studies, PAH compounds, more generalizable food categories, more cooking methods (such as smoking), and addition of seafood. Meta-regression allows parameters to be estimated with separation of between-study heterogeneity, and extrapolation of exposures to more foods. Resulting uncertainty estimates are useful in a probabilistic exposure assessment.

Determination and risk assessment of sixteen polycyclic aromatic hydrocarbons in vegetables

Polycyclic aromatic hydrocarbons (PAHs) are a group of organic environmental pollutants posing a potential risk to human health. This study was constructed to investigate the presence of 16 PAHs in six commonly consumed vegetables collected from the markets in Shandong, China by a quick, easy, cheap, effective, rugged, safe (QuEChERS)-based extraction method coupled with gas chromatography-mass spectrometry (GC-MS). Our results showed that the vegetables were polluted with PAHs at an alarming level, of which celery contained the highest total concentration of PAHs (Σ16 PAH), whereas cucumbers contained the lowest Σ16 PAH. Besides, the dietary exposure of PAHs was assessed in these vegetables based on the maximum Σ16 PAH. The results showed that the populations in Shandong were exposed to 23-213 ng/d of PAHs through these six vegetables, suggesting that vegetables are the major sources of PAHs in the diet. Hence, it is necessary to monitor the PAH levels in vegetables. Our study provides guidance for future legislative actions regarding PAH levels in vegetables in China.

Heavy Metal Pollution and Ecological Assessment around the Jinsha Coal-Fired Power Plant (China)

Heavy metal pollution is a serious problem worldwide. In this study, 41 soil samples and 32 cabbage samples were collected from the area surrounding the Jinsha coal-fired power plant (JCFP Plant) in Guizhou Province, southwest China. Pb, Cd, Hg, As, Cu and Cr concentrations in soil samples and cabbage samples were analysed to study the pollution sources and risks of heavy metals around the power plant. The results indicate that the JCFP Plant contributes to the Pb, Cd, As, Hg, Cu, and Cr pollution in nearby soils, particularly Hg pollution. Cu and Cr in soils from both croplands and forestlands in the study area derive mainly from crustal materials or natural processes. Pb, Cd and As in soils from croplands arise partly through anthropogenic activities, but these elements in soils from forestlands originate mainly from crustal materials or natural processes. Hg pollution in soils from both croplands and forestlands is caused mainly by fly ash from the JCFP Plant. The cabbages grown in the study area were severely contaminated with heavy metals, and more than 90% of the cabbages had Pb concentrations exceeding the permissible level established by the Ministry of Health and the Standardization Administration of the People’s Republic of China. Additionally, 30% of the cabbages had As concentrations exceeding the permissible level. Because forests can protect soils from heavy metal pollution caused by atmospheric deposition, close attention should be given to the Hg pollution in soils and to the concentrations of Pb, As, Hg and Cr in vegetables from the study area.

Composite of PAH-degrading endophytic bacteria reduces contamination and health risks caused by PAHs in vegetables

Vegetables accumulate polycyclic aromatic hydrocarbons (PAHs) at high concentrations when grown in contaminated sites. Inoculation with PAH-degrading endophytic bacteria (EB_PAH) has been recognized as one of the most promising ways to remove PAHs from plant bodies; however, the performance of single endophytic bacteria is generally limited. This investigation used a composite of eight EB_PAH to reduce the contamination and health risk posed by 16 EPA priority PAHs in vegetables including Chinese cabbage (Brassica chinensis L.) and pakchoi (Brassica campestris L.). Composite EB_PAH have strong PAH degradation abilities, and more than 65% of ∑PAH were degraded after 10-day insuspension with composite EB_PAH. Vegetable were contacted with composite EB_PAH by seed soaking (SS) and leaf painting (LP) with an EB_PAH cell incubation at OD_600nm=0.2-1.5. Compared with those in non-inoculated controls, the ∑PAH concentrations in edible parts of Chinese cabbage and pakchoi colonized by composite EB_PAH via SS and LP with bacterial suspension at OD_600nm=0.2-1.5 were 42.07-70.77% and 15.79-53.20% lower, and the incremental lifetime cancer risk (ILCR) values for males and females were 31.78-84.08% and 26.60-83.40% smaller, respectively. SS was the optimal inoculation method for reducing PAH concentrations and ILCR values. Our results indicate that inoculating plants with composite EB_PAH can lower the health risk posed by vegetables contaminated with PAHs, and may be used to mitigate plant PAH contamination.

Heavy metals in contaminated environment: Destiny of secondary metabolite biosynthesis, oxidative status and phytoextraction in medicinal plants

Contamination of soils, water and air with toxic heavy metals by various human activities is a crucial environmental problem in both developing and developed countries. Heavy metals could be introduced into medicinal plant products through contaminated environment (soil, water and air resources) and/or poor production practices. Growing of medicinal plants in heavy metal polluted environments may eventually affect the biosynthesis of secondary metabolites, causing significant changes in the quantity and quality of these compounds. Certain medicinal and aromatic plants can absorb and accumulate metal contaminants in the harvestable foliage and, therefore, considered to be a feasible alternative for remediation of polluted sites without any contamination of essential oils. Plants use different strategies and complex arrays of enzymatic and non-enzymatic anti-oxidative defense systems to cope with overproduction of ROS causes from the heavy metals entered their cells through foliar and/or root systems. This review summarizes the reports of recent investigations involving heavy metal accumulation by medicinal plants and its effects on elicitation of secondary metabolites, toxicity and detoxification pathways, international standards regarding in plants and plant-based products, and human health risk assessment of heavy metals in soil-medicinal plants systems.

Migration and Accumulation of Octachlorodipropyl Ether in Soil-Tea Systems in Young and Old Tea Gardens

The migration and accumulation of octachlorodipropyl ether (OCDPE) in soil-tea systems were investigated using a gas chromatography-electron capture detector (GC-ECD) method in young and old tea gardens. When the residual concentration of OCDPE was 100 g a.i. hm^-2 in soils, the peak concentrations of OCDPE in fresh leaves of young and old tea plants were 0.365 mg/kg and 0.144 mg/kg, taking 45 days and 55 days, respectively. Equations for the accumulation curves of OCDPE in fresh leaves of young and old tea plants were C_t = 0.0227e^0.0566t (R² = 0.9154) and C_t = 0.0298e^-0.0306t (R² = 0.7156), and were C_t = 3.8435e^0.055t (R² = 0.9698) and C_t = 1.5627e^-0.048t (R² = 0.9634) for dissipation curves, with a half-life of 14.4 days and 12.6 days, respectively. These results have practical guiding significance for controlling tea food safety.

Sources and health risks of polycyclic aromatic hydrocarbons during haze days in eastern China: A 1-year case study in Nanjing City

The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) in ambient air were investigated for a 1-year period to assess their sources and health risks during haze days in Nanjing City, eastern China. The highest level of total PAHs (∑₁₆ PAHs) in the gaseous phase during the haze days was 18.0±13.3µg/m³. Their sources may be attributable to pyrogenic products (55.2%), petrochemical refining industry (8.7%), and petrol volatilization (36.1%). The incremental lifetime cancer risk during the haze days exceeded or was close to the priority level of risk (10^-4), indicating that PAH pollution during the haze days has caused public health problems associated with the respiratory system. The priority PAHs in the particle phase are mainly composed of low-ring components (<4 rings), accounting for 65.2-96.8% of the ∑₁₆ PAHs during haze days. These particles are derived from petroleum hydrocarbons (16.5%), incomplete combustion of gasoline (62.2%), and burning of coal and biomass (21.4%). The priority level of risk fell within an acceptable range (10^-7-10^-6). The PAHs in suspended particles can be transported to the surfaces of vegetables by gravitational deposition, causing an increase in PAH concentrations in vegetable leaves. The increased carcinogenic risk associated with human dietary intake was 6.9×10^-5 for S. oleracea, 1.7×10^-5 for B. pekinensis, and 6.2×10^-6 for B. chinensis. These levels were close to the critical value (10^-4), and the potential health risks from dietary intake of PAHs should be prioritized.

Study of the genotoxicity of organic extracts from wastewater-irrigated vegetables using in vitro and in vivo biological tests

The purpose of this study was to explore genotoxicity due to organic pollutants in wastewater-irrigated vegetables using biological and chemical analyses. Chinese cabbages from wastewater-irrigated farmland were taken as the research object. For the in vitro test, DNA damage was characterized in rat hepatocytes exposed to organic extracts from the cabbages using the comet assay. For the in vivo tests, mice were exposed to organic extracts from the cabbages. DNA damage was assessed in mouse peripheral blood lymphocytes (PBLs), and chromosome damage was assessed in bone marrow cells using the comet assay and micronucleus test, respectively. For the chemical analysis, gas chromatography-mass spectrometry (GC/MS) was used to analyze the organic compounds in the organic vegetable extracts. The in vitro test results showed that the comet tail lengths of the DNA in rat hepatocytes were significantly increased in the group dosed with 0.36 g/ml (P < 0.05), and the comet tailing rates of the hepatocytes were significantly increased in the groups dosed with 0.24 and 0.36 g/ml (P < 0.05). The in vivo test results indicated that the comet tail lengths of the DNA in mouse PBLs were increased in the low- and high-dose groups and that the comet tailing rate of the PBLs was increased in the high-dose group (P < 0.05). The chemical analysis results showed that the total organic content in the organic vegetable extracts from the wastewater-irrigated area (1.355 mg/kg) was significantly higher than the content in the cabbage samples from the clean-water-irrigated area (0.089 mg/kg). This finding indicated that wastewater irrigation can cause organic pollution with genetic toxicity in vegetables. This study also showed that in vivo and in vitro biological tests can reflect the joint toxicity of organic pollutants, and the test results were in accordance with the chemical analysis of the organic pollutant compositions.

A Review on the Abundance, Distribution and Eco-Biological Risks of PAHs in the Key Environmental Matrices of South Asia

Polycyclic aromatic hydrocarbons (PAHs) are consistently posing high risks to human/biota in developing countries of South Asia where domestic areas are exposed to biomass burning and commercial/industrial activities. This review article summarized the available data on PAHs occurrence, distribution, potential sources and their possible risks in the key environmental matrices (i.e., Air, Soil/Sediments, Water) from South Asian Region (SAR). Available literature reviewed suggested that PAHs concentration levels were strongly influenced by the monsoonal rainfall system in the region and it has been supported by many studies that higher concentrations were measured during the winter season as compared to summer. Biomass burning (household and brick kilns activities), open burning of solid wastes and industrial and vehicular emissions were categorized as major sources of PAHs in the region. Regional comparison revealed that the contamination levels of PAHs in the water bodies and soil/sediments in SAR remained higher relatively to the reports from other regions of the world. Our findings highlight that there is still a general lack of reliable data, inventories and research studies addressing PAHs related issues in the context of environmental and human health in SAR. There is therefore a critical need to improve the current knowledge base, which should build upon the research experience from other regions which have experienced similar situations in the past. Further research into these issues in South Asia is considered vital to help inform future policies/control strategies as already successfully implemented in other countries.

Risk assessment of heavy metals via consumption of vegetables collected from different supermarkets in La Rochelle, France

In this study, a food survey was carried out with two purposes: (1) to investigate the levels of nickel (Ni), zinc (Zn), and copper (Cu) in various vegetables randomly collected in supermarkets of La Rochelle and (2) to assess the potential health risk for consumers by estimating the daily intake (EDI) and the target hazard quotient (THQ) for each heavy metal. The concentrations of Ni, Cu, and Zn in selected foodstuffs were detected within the following ranges: (3.2-9.6), (25.2-104.7), and (10.8-75.6) mg/kg (DW), respectively. Results showed that metals are more likely to accumulate in fruit vegetables (8.8, 63.8 and 47.8 mg/kg DW for Ni, Cu, and Zn, respectively), followed by leafy vegetables (6.5, 60.9 and 42.6 mg/kg DW for Ni, Cu, and Zn, respectively) and finally root vegetables (5.4, 40.0 and 27.3 mg/kg DW for Ni, Cu, and Zn, respectively). The levels of the metals match with those reported for similar vegetables from some other parts of the world. For all foodstuffs, EDI and THQ were below the threshold values for Cu (EDI 11.30; THQ 0.283) and Zn (EDI 6.86; THQ 0.023), while they exceeded the thresholds for Ni (EDI 20.71; THQ 1.035), indicating an obvious health risk over a life time of exposure.