Atmospheric deposition of Pb and Cd in the Cedrus atlantica for environmental biomonitoring

Concentration of heavy metals in soil and leaves of Conocarpus Erectus Tree: A Biomonitoring Study, Ahvaz, Iran

Heavy metals biomonitoring was performed using the Conocarpus erectus tree in Ahvaz city. Composite leaf and soil samples were collected from 23 selected stations. The concentrations of heavy metals (Pb, Zn, Cd, Cu, Fe and Mn) in leaf and soil samples, and bioavailability of metals in soil samples were determined. Examination of soil physicochemical parameters proved neutral to slightly alkaline nature, and low organic matter content in the soil samples. The mean concentration of heavy metals in soil was: Fe > Mn > Zn > Pb > Cu. Ecological risk assessment of heavy metals was in the range of safe to low risk (RI < 150). Although the concentration of metals in the more polluted areas was higher in both leaf and soil samples, there was no significant relationship between the concentrations of metals in the leaf and soil samples. This relationship is even lower between the bioavailable component of metals in the soil and the concentration of metals in the leaves. Transfer factor values based on total contents of metals in soil samples indicated that Conocarpus erectus is mostly contaminated with Zn and Cu. The results of Accumulation factor of plant revealed that Pb, Zn, and Fe were mostly enriched in the plant by anthropogenic activities. MAI values in heavy and light traffic, and industrial areas were 11.88, 8.01 and 8.15, respectively. In general, it is evident that the Conocarpus erectus leaves accumulate heavy metals in polluted areas, so it can be used as a bioindicator of air pollution with heavy metals in regions with similar conditions.

The European trees phyllosphere characteristics and its potential in air bioremediation

The air pollution remediation is naturally carried out by plants. Their overground parts called phyllosphere are a type of a natural filter on which pollutants can be adsorb. Moreover, microbial communities living in phyllosphere perform a variety of biochemical processes removing also chemical pollutants. As their pollution is nowadays a burning issue especially for highly developed countries, the development of effective and ecological technologies for air treatment are of the utmost importance. The use of phyllosphere bacteria in the process of air bioremediation is a promising technology. This article reviews the role of phyllospheric bacteria in air bioremediation processes especially linked with the moderate climate plants. Research results published so far indicate that phyllosphere bacteria are able to metabolize the air pollutants but their potential is strictly determined by plant-phyllospheric bacteria interaction. The European tree species most commonly used for this purpose are also presented. The collected information filled the gap in the practical use of tree species in air bioremediation in the moderate climate zone.

Impacts of atmospheric deposition on the heavy metal mobilization and bioavailability in soils amended by lime

Atmospheric deposition is an important source of heavy metal in agricultural soils, but there is limited research on the mobility of these metals in soil and their impact on soil amendment. Here, we performed a dust incubation experiment in soils in the laboratory and a factorial transplant experiment at three field sites with a gradient of atmospheric deposition to examine the impacts of atmospherically deposited heavy metals (Cu, Cd, and Pb) on the mobility and bioavailability in soils with and without lime applications. Results showed that the atmospherically deposited heavy metals showed high mobility and were primarily presented in the soluble ionic fractions in the wet part and acid-exchangeable and reducible fractions in the dry part of atmospheric deposition. Atmospheric dust addition caused the 2p3/2 and 2p1/2 electrons of Cu atoms in uncontaminated soils to transition the 3d vacant states, resulting in similar copper absorption peaks as atmospheric particles by the observation of X-ray absorption near-edge spectroscopy (XANES). In the field, atmospheric deposition can only increase the mobile fractions in the surface soils, but not in the deeper layers. However, the deposition can increase the soluble and diffusive gradients in thin films (DGT)-measured bioavailable fractions in profile along with the soil depth. Lime applications cannot significantly reduce the mobile fractions of heavy metals in the surface soils exposed to atmospheric deposition, but significantly reduce the heavy metal concentrations in soil solutions and the DGT-measured bioavailable concentrations, particularly in the deeper layer (6-10 cm). The major implication is that atmospherically deposited heavy metals can significantly increase their bioavailable concentrations in the plough horizon of soil and constrain the effects of soil amendments on heavy metal immobilization, thereby increasing the risks of crop uptake.

Moss-bag technique as an approach to monitor elemental concentration indoors

The moss-bag technique has been used for many decades to monitor outdoor pollution. More recently, however, the method has been used to monitor indoor air pollution (IAP), as humans spend the majority of their time indoors. The purpose of the research conducted was to evaluate indoor air pollution using active moss biomonitoring. Pleurozium schreberi moss bags were exposed for two seasons (summer and winter), hanging over tile stoves and coal stoves. The selected elements: Al, Cu, Cd, Co, Pb, Zn, V, Ba, Cr, Fe, Mn, Sr, P, Ni, and S were determined by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and, for Hg, by a direct mercury analyzer. The study found the exposure season affected the concentrations of selected elements in 62.5% of cases, and their source was identified. The average concentrations of Co, Ba, Cr, and Sr were higher, and statistically significant, in winter, after a 12-week exposure period of the mosses, regardless of the type of heating or cooking stove owned. The higher phosphorus concentrations obtained in summer indicate physiological stress caused by unfavorable winter exposure conditions. In the future, the number of species used to assess indoor air pollution should be increased and the range of pollutants expanded, along with the identification of their sources, taking residents' lifestyles into account.

Assessment of air pollution tolerance and anticipated performance index of roadside trees in urban and semi-urban regions

Rapid urbanization and rising vehicular population are the main precursors in increasing air pollutants concentration which negatively influences the surrounding ecosystem. Roadside plants are frequently used as the barrier against traffic emissions to minimize the effects of air pollution. They are, however, vulnerable to various contaminants, and their tolerance capacity varies. This necessitates a scientific inquiry into the role of roadside plantations in improved urban sprawl planning and management, where chosen trees could be cultivated to reduce air pollution. The present study assesses biochemical and physiological characteristics to evaluate the air pollution tolerance index (APTI) in Ranchi, Jharkhand. The anticipated performance index (API) was assessed based on calculated APTI and socioeconomic characteristics of a selected common tree species along the roadside at different sites. According to APTI, Mangifera indica and Eugenia jambolana were the most tolerant species throughout all the sites, while Ficus benghalensis and Ficus religiosa were intermediately tolerant towards air pollution. The one-way ANOVA shows no significant variation in APTI throughout all the sites. The regression plot shows the positive correlation of APTI with ascorbic acid among all the parameters. According to API, the Mangifera indica, Eugenia jambolana Ficus religiosa and Ficus benghalensis were excellent and best performers among all the sites. So, the air pollution-resistant tree species can be recommended for roadside plantations for the development of green belt areas in urban regions.

Comparison of the rate of certain trace metals accumulation in indoor plants for smoking and non-smoking areas

Tobacco smoke causes to release severe toxic metals into the environment. It is recognized as the most significant issue in indoor air quality. Pollution and toxic substances in smoke quickly spread and penetrate the indoor environment. Environmental tobacco smoke is responsible for lowering indoor air quality. There is much evidence that poor air quality occurs with inadequate ventilation conditions in indoor environments. The plants have been observed to absorb the smoke in the environment into their own body like a sponge. The plant species in this study can be used easily in almost every office, home, or other indoor areas. Using indoor plants is very beneficial in biomonitoring and absorbing these trace metals. Some indoor plants have shown successful performance as biomonitors for health-damaging pollutants. The study aims to determine the concentration of three trace metals (Cu, Co, and Ni) using five indoor ornamentals frequently used in smoking areas, namely D. amoena, D. marginata, F. elastica, S. wallisii, and Y. massengena. The Ni uptake and its accumulation in S. wallisii, and Y. massengena increased in correlation with smoke areas. However, the rate of accumulation of Co and Cu was found to be independent due to consideration of the environmental emissions. Consequently, our results suggest that F. elastica is more resistant to smoking, whereas S. wallisii would be a better choice as a biomonitoring plant of tobacco smoke.

Variation of Al concentrations depending on the growing environment in some indoor plants that used in architectural designs

Today, most of people's time is spent indoors. Air pollution indoors is much higher than outdoors. Therefore, the effect of indoor air on human health is much more than the outside air. One of the most effective methods of reducing indoor air pollution is the use of plants. However, in order for the plants to be used effectively for this purpose, it is first necessary to determine which plants are the most effective in reducing which pollutants. Within the scope of this study, the Al accumulation potential of seven ornamental plants, which are frequently used in interior architectural designs, was evaluated. Within the scope of the study, the variation of Al concentrations on the basis of species and environment was determined in plants grown in control, smoking environment, and traffic environment. As a result of the study, it was determined that Al concentrations changed statistically significantly both on the basis of environment and species, and the species with the highest Al accumulation potential was difenbahya.

Detection of landscape species as a low-cost biomonitoring study: Cr, Mn, and Zn pollution in an urban air quality

Urban air pollution in cities, among the world's most critical problems, has escalated to such an extent that it threatens human health in many urban centers and causes the death of millions every year. Trace metals are significant among the components of air pollution. Trace metals can endure long without undergoing biodegradation and bioaccumulation in living organisms. Moreover, their concentration in the air increases gradually. Therefore, monitoring metal concentration is extremely important for reliable indicators of environmental pollution. Biomonitoring is an effective method for describing metal concentrations in urban areas. Chromium, manganese, and zinc, selected within the present study, have various adverse effects on plants in high concentrations. Their identification is highly critical for monitoring the pollution level in their regions. This study aimed to determine the Cr, Mn, and Zn concentration changes according to organ, and age in Elaeagnus angustifolia L., Platanus orientalis L., Koelreuteria paniculata Laxm, Ailanthus altissima (Mill.) Swingle, and Cedrus atlantica (Endl.) Manetti ex Carr is 30 years old. The accumulation of metals in the outer bark can be found as follows Zn > Mn > Cr in all species, although Ailanthus altissima (Mill.) Swingle and Platanus orientalis L. can be suitable for biomonitoring tools because concentrations change significantly depending on the airborne metal.