Bioindicators Of Heavy Metal Pollution Research Articles

Enzymatic Modifications, as Biomarker for Heavy Metal Toxicity in Catla catla a Fresh Water Fish

Over the last couple of decades, pollution of the environment has grown to be a significant problem, attracting the curiosity of countless experts from developed as well as underdeveloped countries. Sewage dumping into waterways has a detrimental effect on the aquatic ecosystem and biota since it is the principal sink. As a result of their ability to bioaccumulate and intensify as they ascend food chains, toxic metals are not completely eliminated from the environment. For instance, heavy metals have a tendency to accumulate in the muscular tissues of aquatic species; hence, tissues with elevated levels of toxic metals may be detrimental to the well-being of humans and other animals. Fish have been used as indicator organisms to track contamination in aquatic environments. The fish known as catla catla, an Indian Major carp, is edible and extremely susceptible to even the slightest amount of stress. Fish biomarkers are now often employed to assess the internal and exterior health conditions brought on by toxins.
 The purpose of our investigation was to clarify how biomarkers may be used to track and assess the levels of toxic heavy metals in freshwater Catla catla fish.
 Results: SOD can be used as a bioindicator for heavy metal pollution, according to the current study's findings. These investigations ultimately aim to quantify pollution concentrations that can cause aquatic environments to undergo permanent biological alterations. Though still mild, the amount of toxicity was approaching to danger. To preserve a healthy and pristine environment, public and government-sponsored initiatives can be undertaken to restrict those activities that discharge contaminants into the ecosystem in an unscientific way.
 Conclusion: The study comes to the conclusion that in order to evaluate and track the biological state of the aquatic environment, a multiparameter assessment is required.

Assessment of heavy metal concentrations and bioaccumulation in the invasive round goby (Neogobius melanostomus) and associated risks to human health

The round goby (Neogobius melanostomus) is an invasive species that can be used as a raw material in the food industry and also as a bioindicator of heavy metal pollution in the environment. In this study, Cd, Co, Cr, Mo, Ni, and Pb were determined in water, bottom sediment, muscle, liver, gills, and gonads of round goby from Dąbie Lake, Szczecin Lagoon, and Puck Bay (all in southern Baltic Sea) using atomic absorption spectrometry. Fulton’s condition factor, gonadal and hepatosomatic indices (GSI, HSI) were calculated. Based on estimated daily intake (EDI), target hazard quotient (THQ), and carcinogenic risk (CR), we assessed the human health risk related to the consumption of heavy metals in the round goby. The fish had length and weight ranges of 15.0–16.7 cm and 55.3–80.9 g, respectively. Fulton’s condition factor ranged from 1.26 to 2.48 and was highest (p < 0.05) for fish from Dąbie Lake. The range of metal concentrations (in μg kg−1) ranged from 2.92 (Cd in muscles of fish from Szczecin Lagoon) to 106.4 (Ni in muscles of fish from Dąbie Lake). The highest concentrations of Cd, Co, Mo, and Pb were found in livers, Ni in muscles and gonads, and Cr in gills. The calculated EDIs were below the reference oral dose (RfD) and maximum for Cd (1.6% RfD) and Pb (15.1% RfD). The hazard quotient was less than 1. In conclusion, the round goby has a higher potential to accumulate metals from water than from bottom sediments. Consumption of its muscle should not pose a health risk (cancer risk can be considered acceptable). Due to Pb accumulation, moderate consumption should be recommended for pregnant women and children. Finally, our results indicate that the round goby (especially its liver) can be used as a bioindicator to monitor metal contamination of aquatic ecosystems.

Environmental monitoring: Tobara fish as bioindicators of heavy metal pollution in a coastal ecosystem

This study aims to evaluate the liver, gill, and muscle tissue heavy metal accumulation of the thin lip mullet (Chelon ramada) from Ain Ziana Lagoon, Benghazi. The heavy metals included zinc, copper, lead, and manganese. Between September 2021 and August 2022, specimens were collected on a monthly basis. They were identified using DNA barcoding, namely the CO1 gene, which is associated with the sequence that is BankIt in the NCBI gene bank (accession number OR533708). The research tracked the lagoon's physicochemical characteristics, finding that heavy metal concentrations spiked in the summer and that water temperature, pH, and salinity varied throughout the year. Except for copper in the winter, lead, manganese, and copper levels were all above acceptable limits, according to a comparison with EPA (2005) regulations. On the other hand, zinc levels were under these limitations. The amounts of all metals in the sediment regularly exceeded the limits set by the EPA. Zinc and manganese levels in fish tissues were within the approved ranges according to WHO and FAO standards but lead and manganese levels were far higher than allowed, indicating possible pollution from sewage or industrial sources. There were noticeable seasonal patterns in bioaccumulation, especially during the warmer months, but manganese did not exhibit a distinct pattern. Also noted that the thin lip mullet's mineral absorption and release capacities varied with the different seasons and tissues. Lastly, the Metal Pollution Index (MPI) showed that there was a larger possibility for bioaccumulation in the liver, gill, and muscle during the study period.

Seagrass as a Bioindicator for Heavy Metal Pollution in Semi-Enclosed Marine Ecosystems

This study delves into utilizing Seagrass as a bioindicator for heavy metal detection in semi-enclosed marine ecosystems, with a specific focus on the Jordanian coast of the Gulf of Aqaba. The research evaluates the relationship between human activities and the responses of marine organisms, employing the seagrass species Halophila stipulacea as a key subject. This research examines the ability of seagrass to sense and respond to environmental changes, particularly in terms of trace metal accumulation. These accumulations serve as indicators of the marine environment's health and the extent of human impact. Observations revealed differences in trace metal concentrations across three distinct habitats. Notably, varying levels of Cadmium (Cd) and Chromium (Cr) were found in seagrass leaves, while Copper (Cu) and Iron (Fe) were more prevalent in roots. Increased concentrations of Malondialdehyde (MDA), a marker of environmental stress as indicated by lipid peroxidation (LPO), point to a potential link between human activities, such as boating, and the health of seagrass. These findings underscore the complex interactions between marine biology, environmental management, and the innate abilities of organisms to perceive and adapt to changes in their environment. The study bridges the gap in understanding organismal responses to environmental changes and emphasizes the need for ongoing research. Such research is crucial to comprehend the broader effects of environmental shifts on marine life. By continuously monitoring trace metal levels and understanding the responses of seagrass over time, this study lays the groundwork for innovative conservation and management strategies. These strategies are aimed at protecting vital marine environments from the growing impacts of human disturbances.

Data of bioaccumulation and biomagnification from soil in biota nettle-snail (Urtica dioica, L and Helix pomatia,L) of heavy metal (Pb, Zn, Ni) pollution of mining activity in Mitrovica.

ABSTRACT&#x0D; In this research project, we measured the impact and distribution of the activity of minning Trepça Complex in Mitrovica on the concentrations of heavy metals (Pb, Zn, Ni) in soil, plant (Urtica dioica,L) and shell of snail (Helix pomatia).&#x0D; Introdiction: Large quantities of these metals come from natural and anthropogenic sources including mining activity, agriculture, pesticide use, industrialization, and inadequate disposal of mineral waste and artificial fertilizers. These inorganic pollutants are deposited in the soil, water, and atmosphere in various forms of complexes and are thus transmitted from plants, animals to humans. Climatic factors such as winds, rains, and temperatures are believed to be major contributors to the spread over time and space of heavy metals in the environment.&#x0D; Materials and methods: Soil samples, nettle plant (Urtica dioica, L), and snail (Helix pomatia, L), were collected from the selected pollution source of mine Trepça complex at distances of 1km, 2km, and 5km in the radius circles divided into four geographical areas. Also the control samples are collected in unpolluted site Opoja-Dragash municipalty. The samples were digested in microwave at 2000C for 45 min and have been read in flame absorber Analyticjena Contra AAA.&#x0D; Results: Higher concentrations of Pb, Zn, and Ni were recorded in the southern parts of the country compared to that control with significant differences (p&lt;0.01). Bioaccumulation and biomagnification levels of these heavy metals have also been recorded in the roots, stalks, and leaves of the stinging nettle plant (Urtica dioica, L) as well as in snail shells (Helix pomatia, L.).&#x0D; Conclusions: The results show that the stinging nettle plant has translocated larger amounts of these heavy metals especially Pb along with the vegetative organs wherefrom these they are carried in the snail shell, which is fed on the stinging nettle plant.&#x0D; Also, results shown that the nettle plant Urtica dioica can be used in phytoremediation process whereas snail Helix pomatia can be used like bioindicator of heavy metal pollution.&#x0D; &#x0D;

Seasonal Variation and Association of Heavy Metals in the Vital Organs of Edible Fishes from the River Jhelum in Punjab, Pakistan.

The toxic effects of heavy metals are drastic, including accumulation. Fish species are important bio-indicators of heavy metal pollution in aquatic bodies. The current study aimed to assess the seasonal variation of heavy metals in the vital organs of mostly consumed fishes in River Jhelum, Pakistan. Samples of fish, including Wallago attu (Malhi), Rita rita (Khagga), and Mystus seenghala (Singhari), were collected from four different sites, i.e., Khushab, Muhammad Wala (M. Wala), 8.R.D and Rasool barrage during summer and winter seasons. Heavy metals such as iron (Fe), lead (Pb), chromium (Cr), cobalt (Co) and Cadmium (Cd) were estimated through acid digestion and spectrometric analysis. Results showed a significantly higher (P < 0.05) amount of these metals in the liver, followed by the kidneys of fish species. There were seasonal variations in the absorption of these metals as well. Cr (11.71) and Fe (58.66) were detected in higher amounts in Khagga which showed the greatest affinity for certain metals in some cases. In contrast, Singhari showed the greatest affinity to other metals in other cases. Comparative analysis revealed that there was a highly significant (P < 0.05) difference for the accumulation of almost all metals in both seasons and summer had the highest concentration of Cd, Pb, Co, Cr and Fe as compared to winter in all four sampling stations in the case of kidney and liver of all the three fishes. Elevated levels of heavy metals were detected in the summer due to increased temperature. Heavy metals found in the River Jhelum may demonstrate that metals can significantly affect the fish species.

Gastropods as bioindicators of heavy metal pollution in the Banyuasin estuary shrimp pond area, South Sumatra, Indonesia

The supply of shrimp ponds water sources in this research utilizes water input from the waters of the Banyuasin River Estuary, which brings in heavy metal pollutant particles due to anthropogenic pressure. The potential for accumulation of heavy metals can occur in gastropods which are bioindicators of the pond environment. In this study, we present data on gastropods abundance and community structure concerning environmental physicochemical factors and heavy metal accumulation. Sampling was carried out in November 2021 at five observation stations spread over three shrimp ponds. The collection of gastropod samples used two methods based on achievement targets. The gastropod ecology index calculated the abundance, diversity (H′) values of heavy metals analyzed, namely Pb, Hg, Cu, and Cd. Wet digestion with an acid solution of HNO3 and HClO was performed before measuring the concentration on the Atomic Absorption Spectrophotometer (Shimadzu AA-7000). Furthermore, all data on environmental variables were analyzed by principal components analysis (PCA) to determine the leading variable group for each station. A cluster was formed based on the Bray-Curtis similarity analysis. The results of the gastropod ecology index as a bioindicator showed moderate and low diversity (H′) and evenness (J) values, while dominance (D) was high and moderate. From two species analyzed for heavy metals, Nerita violacea and Telescopium telescopium contained Pb, Hg, and Cu concentrations, but no Cd levels were detected, including in water and sediment. Accumulation of heavy metals in shrimp ponds is not only due to the mass movement of tidal water, some of which contribute, namely the location of the inlet and outlet waterways and the position of the land to the main canal source. In general, these results indicate that the environmental conditions of the pond have accumulated heavy metal pollutants, but its whereabouts cannot be ascertained all the time. These results are sufficient to describe the current situation but need further study its impact on aquaculture production.

Plants as bioindicators of heavy metal pollution

This research was designed to assess metal deposition (Zn, Cr, As, Cd, Hg and Pb) and modifications in photosynthetic pigments, total nitrogen, protein in six plant species (Brachiaria eruciformis, polypogon monspeliensis, Phragmites australis, Cynodon ductylon, Prosopis farcta and Typha domingensis) &nbsp;near Turaq region which was designated as polluted site and comparing it to control site. The results indicated a significantly increased concentration of studied metals in the contaminated area. Phragmites australis shows maximum accumulation of Cr, As, and Hg. The accumulation of Zn, Pb and Cd were highest in Prosopis farcta, Cynodon ductylon and polypogon monspeliensis, respectively. Pigments and proteins were found in lower amounts in plants grown on polluted soil. Metals were negatively correlated with pigments, total nitrogen and proteins in all of the studied plants. The data demonstrated the existence of metals in the plant body in both regions, indicating that there is a variation in metal absorption capacities.

DNA barcoding of marine macroalgae as bioindicators of heavy metal pollution

Metal pollution in the marine coastal environment is an important topical issue. In this study, the water quality in five locations along the Alexandria coast (Eastern Harbor, El-Tabia pumping station, El Mex Bay, Sidi Bishir, and Abu Talat) was assessed by measuring physicochemical parameters from water samples. Depending on the morphological classification of macroalgae, the collected morphotypes were related to Ulva fasciata, Ulva compressa, Corallina officinalis, Corallina elongata, and Petrocladia capillaceae. Corallina officinalis and Corallina elongata demonstrated a high capacity for Cd, Pb, and Ni accumulation, and the highest values of Fe, Cu, and Mn were reported in Ulva fasciata and Ulva compressa. Two standard markers were applied, and results showed that the morphological classification matched the molecular data. Moreover, the analysis of algae can only reflect the accumulation of metals. The conclusion is that Ulva compressa and Corallina officinalis are potentially suitable indicators of localized short-term heavy metal pollution.

Bagarius bagarius, and Eichhornia crassipes are suitable bioindicators of heavy metal pollution, toxicity, and risk assessment

Water quality index (WQI) of Narora channel and health of endemic fish Bagarius bagarius and plant Eichhornia crassipes, district Bulandshahar, Uttar Pradesh, India were studied. Among the physicochemical properties of water, pH, D.O, Cr, Fe, Ni, and Cd were above the recommended standards. These factors lead to high WQI (4124.83), indicating poor quality and not suitable for drinking and domestic usage. In fish tissues, the highest metal load was reported in the liver (58.29) and the lowest in the kidney (33.73). Heavy metals also cause a lowering of condition indices. As expected, decreased serum protein (− 63.41%) and liver glycogen (− 79.10%) were recorded in the exposed fish. However, blood glucose (47.22%) and serum glycogen (74.69%) showed elevation. In the plant, roots (21.50) contained the highest, and leaves (16.87) had the lowest heavy metal load. Bioaccumulation factor (BAF) > 1, indicates hyperaccumulation of all metals. E. crassipes roots showed the highest translocation factor (TF) > 1 for Ni (1.57) and Zn (1.30). The high mobility factor (MF) reflected the suitability of E. crassipes for phytoextraction of Mn, Cd, Zn, Fe, Ni, and Cu. Moreover, Bagarius sp. consumption could not pose any non-cancer risk. Although, lower cancer risk can be expected from Ni and Cr.

An overview of the impact of heavy metal accumulation on marine molluscs

Seafood, particularly bivalves, is an excellent source of balanced food. However, due to the rising concentration of heavy metals in the aquatic environment, it can have a negative effect on public health. Heavy metals are common inorganic pollutants in the environment, and their presence poses a significant threat to human beings due to their toxic effect on the biotic system. Various biological and geochemical factors influence the uptake and bioaccumulation of these heavy metals in marine organisms. As a result of the contamination from industrial wastage and domestic discharges from urbanized areas, marine organisms, including molluscs, reflect the rising level of environmental pollution. This study aimed to gather information on environmental contamination in different aquatic organisms and molluscs. Despite their potential as bioindicators for heavy metal pollution in aquatic organisms, there needs to be more research on nutritional composition and bioaccumulation in molluscs.

EVALUATION OF SPIROGYRA SP. AS A BIOINDICATOR OF HEAVYMETAL POLLUTION IN A TROPICAL AQUATIC ENVIRONMENT

Due to the wide occurrence of environmental pollution, heavy metals need to be closely monitored in the aquatic environment because of its ecotoxicological effects on biota. In this regard, biomonitoring as a tool for the assessment of metal pollution in aquatic ecosystem is quite appealing. Therefore, this study was conducted to investigate algae as a potential bio indicator ofheavy metal pollution in an aquatic environment in Fiji. Spirogyra sp. was sampled from a mining impacted water resource and analysed for heavy metals (manganese, copper, chromium, lead and zinc) using atomic absorption spectrometry. The order of metal accumulation in Spirogyra sp. wasfound as Mn &gt; Cu &gt; Cr &gt; Pb &gt; Zn. The results show that Spirogyra sp. is capable of accumulating heavy metals from polluted water and may be used a bioindicator species in environmentalmonitoring. Finally, the elevated heavy metal levels in the VGR aquatic environment could posean ecological risk and appropriate remediation strategies are recommended to minimise adverse impacts to aquatic life.

Ectomycorrhizal Mushrooms as a Natural Bio-Indicator for Assessment of Heavy Metal Pollution

Environmental changes and heavy metal pollution are some of the consequences of anthropogenic activities. Many ecosystems, including edaphic ecosystems, suffer from the effects of pollution. The accurate assessment of soil heavy metal contamination leads to better approaches for remediating soils. The exploration of different ways, including biological methods, to conduct environmental monitoring is still ongoing. Here, we focus on reviewing the potential of ectomycorrhizal fungi as a natural indicator of soil heavy metal pollution. Mycorrhizal fungi fulfill basic criteria required as natural bio-indicators for heavy metal contamination. These fungi use different mechanisms such as avoidance and tolerance to survive in metalliferous soils. Thus, we promote ectomycorrhizal fungi as natural indicators. This review also synthesizes existing research on ectomycorrhizal mushrooms as natural bio-indicators for heavy metal pollution and the elaboration of mechanisms, by which ectomycorrhizal fungi meet the criteria required for a successful bio-indicator.

Honeybees as Bioindicators of Heavy Metal Pollution in Urban and Rural Areas in the South of Italy

The honeybee (Apis mellifera L.) has been used in several studies for monitoring the environmental health status in terms of pollution, due to its wide-ranging foraging flights. Based on this consideration, this study aimed to analyze heavy metal pollution in Molise Region (Italy), by investigating five sites characterized by different levels of contamination. Furthermore, the authors carried out a sampling activity for a long period, in order to obtain a complete dataset. In this way, detailed information about the status of the environments was able to be obtained. The main purpose of this work was to assess the health status of Molise Region and to confirm the suitability of honeybees as environmental bioindicators of heavy metal pollution, by analyzing their variability over time and space. Furthermore, the study compared the health status associated with contamination in terms of heavy metals with that in two different areas of Italy, using hierarchical cluster analysis and principal component analysis, to evaluate the correlation existing among the three different areas of Italy. Following the findings, the authors suggest the use of honeybees as a bioindicator for heavy metal pollution in air quality studies.

The use of green mussel as bioindicator of heavy metal pollution in Indonesia: a review.

Asian green mussel is a marine animal that is used as food by most Indonesians. The mussels are widely cultivated in tropical countries such as Indonesia, Malaysia, Thailand, and other Asian countries. The mussel, known as perna viridis, is marine biota that is a filter feeder in the waters. Therefore, the quality of its meat is greatly influenced by the quality of the sea in its habitat. It is a food that is quite popular with the community but can endanger public health due to the accumulation of heavy metals. This study used a literature review by collecting data related to heavy metal concentrations in green mussel tissue in Indonesia. The results showed that the mussels from several sampling locations still exceeded the maximum acceptable limits of lead (Pb), mercury (Hg), and cadmium (Cd) concentration according to the standards of the food and drug administration of the Republic of Indonesia. Consumption of green mussels can increase health risks if you frequently consume them from cultivating or catching locations that have been contaminated with heavy metals.

Lead and Zinc Concentrations in the Gill, Liver and Parasito-Fauna of Sarotherodon melanotheron iIn Makoko Lagoon, Lagos State, Nigeria

Morphometric and meristic features, metal accumulation and chemical composition of Sarotherodon melanotheron and its intestinal parasites were investigated in August, 2013. The Standard length of Sarotherodon melanotheron range between 13.10-21.50 cm with Mean ± SD of 16.15 ± 1.97, (p<0.001) and Head length range from 1.50-2.70 with Mean ± SD of 2.15 ± 0.28, (p<0.001). Heavy metal concentrations were determined in water, sediment, intestinal parasites, gills and liver of Sarotherodon melanotheron were analysed using Atomic Absorption Spectrophotometry to determine concentration of Pb and Zn. Metals in the water, sediment and parasites were above WHO level. The concentration of Lead and Zinc were higher in the sediment (Pb-18.82 and Zn-21.52) than the water (Pb-2.66 and Zn-15.41). The liver accumulated highest concentration of Lead and Zinc than the gill and parasite. The trend of lead accumulation was; gill (0.86)<parasite (0.98)<liver (3.54). This accumulation followed similar trend in zinc sampled, the mean concentrations for zinc; parasites; (Zn) (mg/l); 3.39, p<0.01, gill; (Zn)(mg/l); 0.72, p<0.01, liver; (Zn) (mg/l); 11.04, p<0.01. Fish parasites, particularly intestinal acanthocephalans and cestodes, accumulated heavy metals at concentrations significantly higher than those in fish tissues or the environment; hence, they could be used as bioindicators of heavy metal pollution. It is important to continue monitoring heavy metals concentration in waters, sediments and fish of Makoko lagoon so as to assess trends in heavy metal behavior in the area.

A Machine Learning Approach in Analyzing Bioaccumulation of Heavy Metals in Turbot Tissues.

Metals are considered to be one of the most hazardous substances due to their potential for accumulation, magnification, persistence, and wide distribution in water, sediments, and aquatic organisms. Demersal fish species, such as turbot (Psetta maxima maeotica), are accepted by the scientific communities as suitable bioindicators of heavy metal pollution in the aquatic environment. The present study uses a machine learning approach, which is based on multiple linear and non-linear models, in order to effectively estimate the concentrations of heavy metals in both turbot muscle and liver tissues. For multiple linear regression (MLR) models, the stepwise method was used, while non-linear models were developed by applying random forest (RF) algorithm. The models were based on data that were provided from scientific literature, attributed to 11 heavy metals (As, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Ni, Zn) from both muscle and liver tissues of turbot exemplars. Significant MLR models were recorded for Ca, Fe, Mg, and Na in muscle tissue and K, Cu, Zn, and Na in turbot liver tissue. The non-linear tree-based RF prediction models (over 70% prediction accuracy) were identified for As, Cd, Cu, K, Mg, and Zn in muscle tissue and As, Ca, Cd, Mg, and Fe in turbot liver tissue. Both machine learning MLR and non-linear tree-based RF prediction models were identified to be suitable for predicting the heavy metal concentration from both turbot muscle and liver tissues. The models can be used for improving the knowledge and economic efficiency of linked heavy metals food safety and environment pollution studies.

Macrozoobenthos Diversity as a Bioindicator of Heavy Metal Pollution in Segara Anakan Lagoon, Cilacap District, Indonesia

Various methods are available for monitoring pollution levels in surface water and sediments, including using organisms as bioindicators. Segara Anakan Lagoon is an estuarine ecosystem that could be affected by contaminants transported by rivers. Pollution sources include pesticides and fertilizers from upstream agricultural areas, domestic waste, and shipping traffic. Macrozoobenthos are among the organisms commonly used as bioindicators of environmental pollution. Macrozoobenthos live at the bottom of the water column, and as deposit feeders, they lend themselves to use as bioindicators. The structure of the macrozoobenthos community in Segara Anakan has changed, as evidenced by the diversity and abundance of benthic species. Furthermore, environmental pollution parameters, such as heavy metal concentrations in water and sediments, are relatively high in the lagoon. Concentrations of Hg, Pb, Cd, and Cr varied among collection sites, with average concentrations of 0.04, 4.4, 1.2, and 1.4 ppm, respectively. In general, the abundance of macrozoobenthos was low at collection stations with high heavy metal concentrations, demonstrating that heavy metal pollution has occurred in Segara Anakan. Correlation tests between macrozoobenthos and heavy metal concentrations in water and sediments yielded r-values of > 0.8225 and 0.7473, respectively.

Effect of sampling time on the heavy metal concentrations of brown algae: A bioindicator study on the Arabian Gulf coast

Macroalgae have often been studied as bioindicators for heavy metal pollution on sea coasts including the Arabian Gulf. On the Arabian Gulf coasts, heavy metals are continuously being released by industrial activities and therefore, pollution monitoring is needed. Biomonitoring studies using macroalgae has given highly different assessments due to the variability in algal species and sampling time points. We carried out a systematic monthly sampling of brown algae (Phaeophyta) from three locations on the western coast of the Arabian Gulf between September and February 2018. One urban area (Uqair) and two oil refining areas (Ras Tanura and Jubail) were monitored due to they have a common brown macroalgae species composition. The incidence of Cystoseira myrica, C. trinodis C. osmundacea, Hormophysa cuneiformis, Sargassum aquifolium, S. latifolium, S. filipendula and Padina boryana varied among the sites and with the time of year within the sites. The concentrations of Co, Cd and Pb varied among the sampling sites, the algal species and the sampling time points remarkably. A tentative time-trend increasing towards February was observed for some species. However, it appeared that neither optimum sampling time point, nor superior brown algae species could be recommended. The highest heavy metal accumulation was observed in Padina boryana. However, this species grew only on the two oil polluted sites. We concluded that some brown algae species can be used for biomonitoring heavy metal pollution on the western coast of the Arabian Gulf. The species incidence should be monitored systematically and the species used should be chosen locally and sampled at the same time of the year.

Honeybees and their products as bioindicators for heavy metal pollution in Malta

In this study, honeybees, propolis, air, soil and plant samples were gathered from two contrasting sites Ħal Luqa (industrial area) and L-Imġarr (agricultural area) in mainland Malta. Superficial heavy metals were extracted from the samples and tested using microwave plasma-atomic emission spectrometry in order to determine the concentrations of Ag, As, Cd, Cr, Cu, Pb, Sn, Zn, Ni and Hg. The honeybee and propolis samples were digested using nitric acid and hydrogen peroxide and then ashed using a muffle furnace in order to prepare mineral solutions. Simultaneously the air samplers, soil and plant samples were washed using de-ionised water in order to extract the heavy metals settling on sample surfaces. Different methods of filtration were used in order to extract the metals from the surfaces of the samples. The most abundant metals in honeybees and propolis, and on plant and soil samples, were Sn and As (p&lt;0.0001). In air samples0, the most abundant metal was Pb followed by Sn (p&lt;0.05). These findings indicate that the honeybee and its propolis are good indicators for Sn and As contamination.