Metal accumulation in Raphanus sativus and Brassica rapa: an assessment of potential health risk for inhabitants in Punjab, Pakistan

Foraging Activity of Honey Bees (Apis mellifera L., 1758) and Exposure to Cadmium: a Review

Honey bees are commonly exposed to a broad spectrum of xenobiotics, including heavy metals. Heavy metal toxicity is of concern in the context of global pollinator declines, especially since honey bees seem to be particularly susceptible to xenobiotics in general. Here we summarize current knowledge on the interplay between cadmium, one of the most toxic and mobile elements in the environment, and honey bees, the primary managed pollinator species worldwide. Overall, cadmium pollution has been shown to be ubiquitous, affecting industrial, urban and rural areas alike. Uptake of this heavy metal by plants serves as the primary route of exposure for bees (through pollen and nectar). Reported cadmium toxicity consists of lethal and sublethal effects (reduced development and growth) in both adult and larval stages, as well as various molecular responses related to detoxification and cellular antioxidant defence systems. Other effects of cadmium in honey bees include the disruption of synaptic signalling, calcium metabolism and muscle function.

Stress mitigation by riparian flora in industrial contaminated area of River Chenab Punjab, Pakistan

Faisalabad is a major industrial area in Pakistan's Punjab province that discharges wastewater into the Chenab River. Industrial effluents in Faisalabad are predicted to pose a significant threat to the riparian vegetation of the Chenab River and nearby vegetation. Heavy metal pollution of plants, water, and soils is one of the biggest problems worldwide that needs to be addressed because heavy metals above normal levels are extremely dangerous to both riparian vegetation and wildlife. The results indicated high levels of pollution in the industrial effluents as well as in the river in terms of salinity, metal toxicity, TSS, TDS, SAR, the acidic and alkaline nature of the industrial effluents, and the spread of industrial effluents up to 15 square kilometres in the Chenab River. Despite the higher pollution, four plants were found at all sites: Calotropis procera, Phyla nodiflora, Eclipta alba and Ranunculus sceleratus. It was found that most of the selected plants were phytoaccumulators, making them best suited to survive in harsh environments such as those with industrial pollution. The Fe concentration in the plant constituents was the highest, along with Zn, Pb, Cd, and Cu, all of which were above the permissible limits of the WHO. The metal transfer factor (MTF) was higher in most of the plants studied, and even exceeded 10 at some severely affected sites. Calotropis procera proved to be the most suitable plant for growth on drainage systems and also at river sites, as it had the highest importance value across all sites and seasons.

Accumulation of potentially harmful elements (PHEs) in lettuce (Lactuca sativa L.) and coriander (Coriandrum sativum L.) irrigated with wastewater: a systematic review and meta-analysis and probabilistic health risk assessment

Water shortage and stress around the world lead to increasing wastewater reuse for the agricultural sector. In addition to its benefits, it can be a way to transfer pollutants such as potentially harmful elements (PHEs) to the human food chain. Many studies have been conducted for this purpose on various vegetables; however, no comprehensive study has been performed on lettuce (Lactuca sativa L.) and coriander (Coriandrum sativum L.). In this respect, the study was aimed to meta-analyze the PHEs concentration in the edible part of lettuce and coriander vegetables irrigated by wastewater. Carcinogenic risk (CR) and noncarcinogenic risk (non-CR) assessments were also done for consumers. After reviewing 32 included articles (41 studies), the rank order of the PHEs in lettuce was obtained as Fe (194.76 mg/kg) > Zn (133.47 mg/kg) > Cu (55.70 mg/kg) > Ni (26.96 mg/kg) > Pb (12.80 mg/kg) > Cr (9.68 mg/kg) Cd (8.24 mg/kg) > As (1.13 mg/kg) and for coriander Fe (1056 mg/kg) > Zn (79.80 mg/kg) > Cr (28.34 mg/kg) > Ni (24.71 mg/kg) > Cu (17.46 mg/kg) > Pb (13.23 mg/kg) > Cd (2.23 mg/kg). Total target hazard quotient (TTHQ) for adults in all countries except UAE, France, and Kenya and for children all countries except Kenya was more than 1 value. The carcinogenic risk for adult groups in Nigeria, France, China, and Iran countries was not acceptable (CR > 1E-4). As a consequence, it can be noted that wastewater reuse in the agriculture sector can endanger the health of consumers.

Appraisal of chromium in chicken reared on maize irrigated with sewage water

In the present study, the outcome of sewage, canal, and ground water on the chromium (Cr) concentration in corn and ultimately in chicken body parts was reported. To evaluate Cr level, atomic absorption spectrophotometer (Flame Atomic Absorption Spectrophotometer AA 6300, Shimadzu Japan) was used. The highest level of Cr in grains (0.50 ± 0.05 mg/kg), shoots (0.90 ± 0.01 mg/kg), and roots (1.01 ± 0.02 mg/kg) were noticed in the Sadaf variety watered with canal water. The least concentration of Cr was recorded in grains (0.07 ± 0.01 mg/kg), shoots (0.59 ± 0.01 mg/kg), and roots (0.71 ± 0.01 mg/kg) of Pearl variety irrigated with ground water. The maximum concentration of chromium in the blood (1.68 ± 0.02 mg/kg) and bones (1.26 ± 0.24 mg/kg) was observed in chicks fed on Millet Research Institute (MMRI) grains reared with the sewage water. The lowest concentration was observed in the blood (1.60 ± 0.04 mg/kg) and in bone (0.80 ± 0.01 mg/kg) of the chicks fed Pearl variety grains reared with canal water. In the second experiment, the maximum content of Cr was determined in the blood (0.74 ± 0.04 mg/kg) and bones (1.76 ± 0.02 ppm) of chicks consuming Sadaf variety grains reared with canal water and the least concentration in the blood (0.26 ± 0.03 mg/kg) and bones (1.64 ± 0.01 mg/kg) was determined on the consumption of the Pearl variety grains reared with ground water. A similar trend was observed in other body organs. It was concluded that polluted water causes higher accumulation levels of Cr in plant parts and even in animals' body parts after the utilization of such plants.

The formation of fungus-serpentine aggregation and its immobilization of lead(II) under acidic conditions

Serpentine has weak immobilization capacity for Pb(II), especially under acidic conditions. In order to improve its application potential, a new biological modification method was adopted, i.e., the serpentine powder was weathered by Aspergillus niger and the fungus-serpentine aggregation (FSA) formed was investigated for its Pb(II) immobilization potential and underlying mechanism. Batch adsorption of Pb(II) by FSA closely followed the Langmuir model, while the maximum adsorption capacity of FSA (370.37 mg/g) was significantly higher than fungal mycelium (31.85 mg/g) and serpentine (8.92 mg/g). The adsorption process can be accurately simulated by pseudo-second-order kinetic model. Our data revealed the loading of organic matter is closely related to the adsorption of FSA, and the stronger immobilization capacity was mainly related to its modified porous organic-inorganic composite structure with extensive exchangeable ions. Moreover, FSA is an economical bio-material with excellent Pb(II) adsorption (pH = 1-8) along with significantly lower desorption efficiency (pH = 3-8), especially under acidic conditions. These findings provide a new perspective to explore the usage of fungus-minerals aggregation on heavy metals immobilization in acidic environments. Key Points • Co-culture of Aspergillus niger and serpentine produced a porous composite material like fungus-serpentine aggregation. • Fungus-serpentine aggregation has a surprisingly higher adsorption capacity of Pb(II) and significantly lower desorption efficiency under acidic conditions. • The loading of organic matter is closely related to the adsorption of FSA.

A Systematic Review and Meta-analysis to Investigate the Correlation Vegetable Irrigation with Wastewater and Concentration of Potentially Toxic Elements (PTES): a Case Study of Spinach (Spinacia oleracea) and Radish (Raphanus raphanistrum subsp. sativus)

Water shortage and stress around the world lead to the reuse of wastewater in many sectors while the recycling of water in agriculture as one of the most consumed sectors can boost the contamination of crops by potentially toxic elements (PTEs). Therefore, this study was aimed to investigate the correlation between the accumulation of PTEs (Fe, Zn, Cr, Ni, Cu, Pb, As, Cd, and Se) in edible parts of spinach and radish plants and sewage irrigation by the aid of a meta-analysis. Moreover, the non-carcinogenic risk (N-CR) and carcinogenic risk (CR) for health risk assessment of consumers were assessed through actual total target hazard quotient (TTHQact) and carcinogenic risk (CRact). After the screening process, 51 articles with 75 studies were included. According to findings, the rank order of PTEs in spinach and radish were Fe > Zn > Cr > Cu > Ni > Pb > Cd > As > Se and Fe > Zn > Cr > Ni > Cu > Pb > As > Cd > Se, respectively. PTE adsorption by edible parts of spinach (leafy vegetable) was higher than radish. The health risk assessment shows that residents in Iran, India, and China are at N-CR while the population of Iran, India, and Pakistan are facing CR.

A study on the transfer of chromium from meadows to grazing livestock: an assessment of health risk

The present investigation was performed in different district of Punjab to determine the chromium level in soil, forages, and blood plasma of the small ruminants (goat and sheep). The results showed that the mean concentrations of chromium in the soil of Sargodha, Mianwali, and Bhakkar districts were ranged from 1.8 to 2.3, 3.01 to 4.99, and 2.04 to 2.87 mg/kg, respectively. The chromium level was higher in Mianwali compared with Sargodha and Bhakkar. The mean concentrations of chromium in forages which were used for feeding purposes were found between 0.672 and 1.631, 1.493 and 2.612, and 0.7804 and 1.047 mg/kg for Sargodha, Mianwali, and Bhakkar, respectively. The mean concentrations of chromium in blood plasma of goat which consumed the contaminated forages were between 0.666 and 1.269 mg/L in Sargodha, 0.657 and 0.752 mg/L in Mianwali, and 1.39 and 2.37 mg/L in Bhakkar. In blood plasma of sheep, the residual levels of chromium in the districts Sargodha, Mianwali, and Bhakkar were ranged from 0.673 to 1.384, 0.83 to 1.086, and 1.496 to 3.611 mg/L, respectively. In the present research, there was a higher concentration of chromium in blood plasma of sheep from Bhakkar and the lowest was in Sargodha. The chromium level in blood samples was found to be higher than the tolerable level of 1.0 mg/L in all districts. In light of these results, it was concluded that chromium levels in the soil and forages of all sites were present within the safe limit while in blood samples of sheep and goats were found to be above the acceptable limit. Sheep and goats also consume water from river, streams, and ponds and other contaminated water sources. So it might be the reason of higher level of chromium in their blood plasma. Hence, the proper monitoring of study sites will be necessary to prevent the excessive accumulation of chromium in ruminants in the near future.

A study on the seasonal transfer of two metals from pasture to animals: health risk assessment

Accretion of heavy metals in forage is a potential risk to grazing animals due to their uptake by plants and its entrance into the food chain. This study aimed to examine the Mn and Cd concentration from different samples. Sampling was done twice after the interval of 6 months during 2018; five different sites from Chakwal (Pidh, Tobar, Ratoccha, Kalar Kahar Road, Choa Saiden Shah and Chakwal Road, Choa Saiden Shah) were selected. Thirty samples of soil, forage (Acacia nilotica, Ziziphus nummularia, and Acacia modesta), and blood were collected. Forage and soil samples were dried, ground very fine, digested by wet digestion method, and analyzed by atomic absorption spectrophotometer. Samples collected from site I and site II had a very high concentration of heavy metals because these sites were very close to the coal mines and receive higher contamination. Manganese concentration in the soil fluctuated from 5.46 to 1.20, in the forage 6.84 to 1.00, and in the blood 5.21 to 1.03 mg/l, and cadmium concentration in the soil fluctuate from 1.85 to 0.03, in the forage 0.57 to 0.16, and in the blood 1.67 to 0.25 mg/l. Manganese concentration was higher as compared to the Cd. Higher concentration of Mn shows that this metal is due to human activities. Pollution load index value of Cd was higher than 1 in some samples, and the value fluctuates from 0.01 to 1.24 mg/kg. The values of a bioconcentration factor for Mn were greater than 1. Daily intake of metal value fluctuates from 0.01 to 1.03 mg/kg. Health risk index value ranges from 0.03 to 1.09 mg/kg. Health risk index of metals showed the risk which is due to the intake of contaminated fodder. From the soil, the metals can enter forage and bioaccumulate in the food chain. The health risk index was highest for Cd. The result obtained from the present research work indicated that there is a biomagnification of both metals in the food chain due to mining activities.

Assessment of bioaccumulation of cu and Pb in experimentally exposed spiders, Lycosa terrestris and Pardosa birmanica, using different exposure routes

Major concerns exist regarding the environmental and human health risks caused by exposure to heavy metals. Spiders are often used as a model in ecotoxicological studies to assess soil pollution. Here, we measured the bioaccumulation of copper (Cu) and lead (Pb) in spiders, Lycosa terrestris and Pardosa birmanica, by inductively coupled plasma mass spectrometry (ICP-MS). We investigated whether Cu and Pb accumulation differs according to different spider species, single versus combined metal exposure, and routes of exposure. Spiders were exposed to 10 mM CuSO₄ and 10 mM PbCl₂ solutions separately or in combination (10 mM + 10 mM) through different exposure routes (spiked soil and food) for 6 weeks. The effect of metals on the survival and body mass of exposed and unexposed (control) spiders was determined. We found that in both spider species, accumulation of metals increased with exposure time. In single metal exposure, Cu accumulation from food was higher than soil exposure in both spider species, whereas the opposite was observed for Pb. The simultaneous uptake of Cu and Pb significantly decreased from food and soil, respectively. Soil exposure caused more accumulation of metals in L. terrestris than P. birmanica. Metal exposure via contaminated food caused higher mortality compared to soil exposure. Body mass of both spider species was significantly decreased and negatively correlated with metal's concentration. Overall, our results show that bioaccumulation efficiency of Cu and Pb differs significantly in spiders exposed to metal's mixture compared to single metal exposure and is dependent on the exposure route, the type of metal, and spider species. More understanding of the effects of exposure to metal mixture and exposure routes is essential for designing and supporting risk assessment and ecological monitoring programs.

Differences in cadmium absorption by 71 leaf vegetable varieties from different families and genera and their health risk assessment

Leaf vegetables have strong capabilities to take up cadmium (Cd) compared to other vegetable varieties. Until now, the differences in Cd uptake and accumulation by leaf vegetables from different families and genera and the related health risks were unknown. To remedy this, we studied 71 leaf vegetables (multiple genotypes within 17 categories of vegetables) in soil cultivation experiments (3 Cd treatment levels). Results showed that at 2.12 mg kg^-1 Cd treatment, the dry weight of only five genotypic varieties from the families Brassicaceae and Asteraceae significantly decreased compared to the control, suggesting their weak Cd tolerances. Vegetables from the Brassicaceae, Asteraceae, Apiaceae, and Convolvulaceae families had stronger Cd absorption capabilities, whereas those from the Liliaceae and Amaranthaceae families had weaker ones. Cluster analysis found that the 17 vegetable categories could be divided into three groups: vegetables with high Cd accumulation capabilities were Lactuca sativa L.var. ramosa Hort. and Lactuca sativa var. longifoliaf. Lam. Vegetables with moderate Cd accumulation capabilities were bok choy, napa cabbage, choy sum, leaf mustard, Lactuca sativa L., Sonchus oleraceus L., celery, coriander, and water spinach. Vegetables with low Cd accumulation capabilities were cabbage, crown daisy, garlic chive, Allium ascalonicum, Gynura cusimbua, and edible amaranth. Estimated daily intake (EDI) and target hazard quotient (THQ) analysis results showed that 100% genotypes of vegetables from the Apiaceae and Convolvulaceae families had health risks; 100% genotypes of Lactuca sativa L., Sonchus oleraceus L., Lactuca sativa L. var. ramosa Hort., and Lactuca sativa var. longifoliaf. Lam from the Asteraceae family carried high risks. Of vegetables in the Brassicaceae family, 42.9% showed risks. Vegetables from the Amaranthaceae and Liliaceae families, Gynura cusimbua and crown daisy from the Asteraceae family, and cabbage from the Brassicaceae family all displayed relatively low risks (all 100%).

The concentration of potentially toxic elements (PTEs) in the onion and tomato irrigated by wastewater: A systematic review; meta-analysis and health risk assessment

Nowadays, vegetable irrigation with wastewater in developing countries has become a serious issue. In this regard, the current investigation was performed to collect the related data regarding the concentration of potentially toxic elements (PTEs) including Fe, Zn, Cu, Cr, Pb, Ni, and Cd in onion and tomato samples irrigated with wastewater by the aid of a systematic review among the Scopus, Medline and Embase databases between 1/January/1983 to 31/January/2019. Also, the health risk assessment for consumers due to PTEs ingestion via the consumption of onion and tomato was estimated by using target hazard quotient (THQ). In this context, 35 articles with 64 studies out of 779 retrieved citations were included in the meta-analysis. The ranking of different parts of tomato based on Pb, Cd, and Cu concentration was shoot > root > leave > edible part; Fe, leave > shoot > root > edible part; Cr, root > leave > shoot > edible part; Zn, shoot > leave > root > edible part; and Ni, leave > edible part > root > shoot. Moreover, the ratio concentration of Pb, Cd, Cu, Fe, Cr, Zn and Ni in the edible part to leave of onion was 2.92, 6.01, 1.29, 4.17, 0.84, and 3.55, 10.10, respectively. According to findings, the rank order of PTEs in the onion was Fe (43.09 mg/kg-dry weight) > Zn (34.3 mg/ kg-dry weight) > Pb (18.54 mg/ kg-dry weight) > Cu (14.9 mg/ kg-dry weight) > Ni (11.92 mg/ kg-dry weight) > Cr (7.24 mg/ kg-dry weight) > Cd (0.23 mg/ kg-dry weight) and tomato; Fe (139.12 mg/ kg-dry weight) > Zn (29.81 mg/ kg-dry weight) > Cu (25.04 mg/ kg-dry weight) > Cr (14.28 mg/ kg-dry weight) > Pb (9.58 mg/ kg-dry weight) > Ni (9.23 mg/ kg-dry weight) > Cd (4.64 mg/kg-dry weight). However, the concentration of PTEs investigated in the edible part of onion was higher than leaves; their concentrations in the edible part of the tomato were lower than other parts. The health risk assessment indicated that consumers groups are at significant non-carcinogenic risk due to the ingestion of PTEs via consumption of the onion and tomato vegetable wastewater irrigated (THQ > 1). Therefore, the irrigation of vegetables with wastewater should be monitored and controlled by some prevention plans.

Health risk assessment through determining bioaccumulation of iron in forages grown in soil irrigated with city effluent

The irrigation with sewage water can be useful if it has no negative effects on food crop yield, soil pollution, and health of humans. However, it includes various types of contaminants like heavy metals that pollute the soil and crops. In this regard, the aim of this study was to evaluate the possible health risks of heavy metals in forages. Forages both of summer and winter were grown with different water treatments (sewage water and tap water) in Department of Botany, University of Sargodha. The concentration of iron (Fe) in water, soil, and plant samples was determined. The Fe values in tap and sewage water were observed as 0.090 and 0.115 mg/L, respectively. The highest mean concentration of Fe was 9.608 mg/kg in the soil where Trifolium alexandrinum is grown, and the lowest mean concentration was 0.154 mg/kg which occurred in the soil where Trifolium resupinatum is grown in winter. The maximum mean concentration of Fe in the root samples of plants was observed as 2.483 mg/kg in Pennisetum typhoideum, and the minimum mean concentration occurred as 0.390 mg/kg in Zea mays grown in summer. The maximum bioconcentration factor value of Fe was observed for T. resupinatum (5.259) grown in winter. The maximum pollution load index value of Fe was observed for T. alexandrinum (0.1688). The maximum value of daily intake of metals was observed as 0.0731 in Medicago sativa, and the maximum health risk index value was determined as 0.1091 in P. typhoideum.

A multivariate analysis of physiological and antioxidant responses and health hazards of wheat under cadmium and lead stress

Soil contamination with heavy metals is a global issue confronting the environmental pollution and human/animal health. Much work has been done on physiological and antioxidant responses of wheat in hydroponic experiments and health risks from individual heavy metal contamination to human, but limited information is available on their combined application in soil. Therefore, this pot study delineates the uptake of lead and cadmium, as well as physiological responses of wheat and associated health risks under different levels of alone and combined Cd and Pb treatments. Metal uptake increased with their increasing applied levels. The highest Cd (4.24, 1.38, and 0.92 mg kg^-1) and Pb (763.33, 39.63, and 16.35 mg kg^-1) concentrations in root, shoot, and grain, respectively, were observed at highest applied levels (0.4 mM Cd and 10 mM Pb). Furthermore, all the treatments increased lipid peroxidation and activities of superoxide dismutase, catalase, ascorbate peroxidase, and peroxidase, while decreased total chlorophyll contents and membrane stability index. Under combined application of Cd and Pb, the toxicity and detoxification responses of wheat increased compared to alone treatments. Multivariate analysis further confirmed the toxicity and accumulation pattern of metals under alone and combined treatments. Target hazard quotient values of Cd and Pb were < 1 under alone and combined treatments. The health hazard index values of Pb (97.07 and 87.89%) were higher than those of Cd (2.93 and 12.10%) in combined application for human and buffalo, respectively. This study highlights that the multi-metal contamination (Cd and Pb) is detrimental for wheat growth and human/animal health.