Microbial degradation of low-density polyethylene (LDPE) and polystyrene using Bacillus cereus (OR268710) isolated from plastic-polluted tropical coastal environment.

The study focused on marine bacteria, specifically Bacillus cereus, sourced from heavily polluted coastal areas in Tamil Nadu, aiming to assess their efficacy in degrading low-density polyethylene (LDPE) and polystyrene over a 42-day period. When LDPE and polystyrene films were incubated with Bacillus cereus, they exhibited maximum weight losses of 4.13 ± 0.81 % and 14.13 ± 2.41 %, respectively. Notably, polystyrene exhibited a higher reduction rate (0.0036 day-1) and a shorter half-life (195.29 days). SEM images of the treated LDPE and polystyrene unveiled surface erosion with cracks. The energy dispersive X-ray (EDX) analysis revealed elevated carbon content and the presence of oxygen in the treated LDPE and polystyrene films. The ATR-FTIR spectra exhibited distinctive peaks corresponding to functional groups, with observable peak shifts in the treated films. Notable increases were detected in carbonyl, internal double bond, and vinyl indices across all treated groups. Additionally, both treated LDPE and polystyrene showed reduced crystallinity. This research sheds light on Bacillus cereus (OR268710) biodegradation capabilities, emphasizing its potential for eco-friendly waste management in coastal regions.

Exopolymeric substances production by Bacillus cereus KMS3-1 enhanced its biosorption efficiency in removing Cd2+ and Pb2+ in single and binary metal mixtures.

The present study investigated the growth, exopolymeric substance (EPS) production, and biosorption efficiency of strain Bacillus cereus KMS3-1 in the Cd2+ and Pb2+ ions containing single and binary metal-treated broth (50 mg/L). In addition, the interaction of the KMS3-1 strain with Cd2+ and Pb2+ ions in single and binary metal-treated broths was investigated using SEM-EDS, FTIR, and XRD analyses. The results showed that the biosorption efficiency (%) and EPS production of KMS3-1 biomass in both single and binary metal-treated broths had increased with increasing incubation time and were higher for Pb2+ ions than for Cd2+ ions. In the single and binary metal-treated broths, the maximum biosorption efficiency of KMS3-1 for Pb2+ ions were 70.8% and 46.3%, respectively, while for Cd2+ ions, they were 29.3% and 16.8%, respectively, after 72 h. Moreover, the biosorption efficiency of strain KMS3-1 for both metal ions was dependent on its EPS production and peaked at the maximum EPS production. The copious EPS production by KMS3-1 was observed in metal-treated media (50 mg/L), in the following order: Pb2+ ions (1925.7 µg/mL) > binary metal mixtures (1286.8 µg/mL) > Cd2+ ions (1185.5 µg/mL), > control (1099 µg/mL) after 72 h of incubation. This result indicates that the metal biosorption efficiency of the KMS3-1 strain was enhanced by the increased EPS production in the surrounding metal-treated broth. SEM-EDS and FTIR characterization studies revealed that the KMS3-1 biomass effectively adsorbed Cd2+ and Pb2+ ions from the medium by interacting with their surface functional groups (hydroxyl, carbonyl, carboxyl, amide, and phosphate). Moreover, the biosorbed Cd2+ and Pb2+ ions were transformed into CdS and PbS, respectively, by the KMS3-1 biomass. This study suggests that the Bacillus cereus KMS3-1 strain may be a promising candidate for the treatment of metal contamination.

Survey to identify the metal accumulation pathway in humans using hair and nail as biomarkers from fisherfolk population.

Human hair and nail samples from Cuddalore fisherfolk populations were used as biomarkers for assessing metal concentrations in humans. Hair samples from 80 participants (47 men and 33 women) and nail samples from 40 participants (21 men and 19 women) were collected, and the concentrations of Cd, Cu, Pb, and Zn were assessed using an atomic absorption spectrophotometer (AAS). Metal data from AAS were compared with the survey questionnaire's personal and dietary parameters. Results indicate that both personal and dietary parameters may influence metal exposure; however, majority of the sources may have originated from metal-contaminated seafood. Higher metal accumulation in communities, especially those which consume seafood on a daily basis, may increase the possibility for them to get affected by metal-related diseases. Based on environmental parameters, people who live ≤500 m from industrial zones accumulate more metals. Further extensive studies with more individuals and more questionnaire parameters are needed to identify the metal accumulation pathway in humans.

Heavy metal contamination along different tidal zones of a tropical Bay of Bengal coastal environment influenced by various anthropogenic activities.

The spatiotemporal variations of five heavy metals (Cd, Cu, Cr, Pb, and Zn) in the beach sediments along the Tamil Nadu coast sourced from various anthropogenic activities were assessed using atomic absorption spectrophotometry (AAS). Various pollution monitoring indices were computed to clearly understand the metal pollution status along the Tamil Nadu coastline. The metal concentrations in sediments were typically higher in the summer season than in the monsoon season. In the monsoon season, metal concentration followed a decreasing order of Zn > Cr > Cu > Pb > Cd, and in the summer season, the order was Cr > Zn > Cu > Pb > Cd. During the monsoon season, freshwater runoff from the rainfall dilutes the sediments and their trace element load. However, due to a lack of freshwater influx during the summer season, the heavy metals in the sediments get concentrated and showed elevated levels. Geo-accumulation index, ecological risk index, pollution load index, and contamination degree clearly depict that Cd and Pb have higher accumulation and pose greater hazard when compared with other metals. The rivers flowing in the region also transport the heavy metals from the mainland to the estuaries and coastal environments. Metal levels along the Tamil Nadu coast are influenced by various anthropogenic activities persistent along the coastline. Some of the activities that cause metal contamination are mining, milling, electroplating, furnishing, pharmaceutical industries, fishing, harbor activities, urban runoff, and agricultural runoff, which release a variety of toxic metals into the coastal environment.

Ecological risk assessment of metals in the Arctic environment with emphasis on Kongsfjorden Fjord and freshwater lakes of Ny-Ålesund, Svalbard.

The concentrations of five heavy metals (Cd, Cr, Cu, Pb, and Zn) in the sediments, water, phytoplankton, zooplankton, and macroalgae from Kongsfjorden Fjord and the freshwater lakes of Ny-Ålesund in the Svalbard archipelago were determined in order to describe the anthropogenic impacts related to the Ny-Ålesund town. Water samples from nine stations, sediment samples from 23 stations, plankton samples from five stations, and six species of macroalgae were collected and subjected to heavy metal analysis using atomic absorption spectrophotometry (AAS). Only Cu and Zn were detected in the water samples. The plankton samples had only Zn, Cu, and Cr. The average metal concentrations in macroalgae fell in the decreasing order of Cu > Zn > Cr > Cd > Pb. In sediment samples, the metal order was as follows: Zn > Cu > Cr > Pb > Cd. Multivariate statistical analyses including principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to identify the source of the metal contamination. The metals were found to originate from a blend of both anthropogenic and geogenic sources. Pollution monitoring indices including geoaccumulation index (Igeo), contamination factor, contamination degree (Cdeg), pollution load index (PLI), and potential ecological risk (PER) were calculated using the metal data. In the study area, Igeo values of the metals showed pollution grades from 0 (uncontaminated) to 6 (extremely contaminated). Cdeg fell in classes from 1 (low contamination) to 4 (very high contamination). PLI values ranged between 0 and 5.68. PER values expressed that except for a few stations located at higher elevations in the glacial outwash plains, all other sites were highly polluted. The high level of pollution indices in the sites can be attributed to the anthropogenic activities persistent in the study area.

Proportions of Pathogenic Bacteria Isolated from Door Locks and Working Benches in Clinical Laboratory: A Laboratory Based Study.

Background: Numerous studies have revealed the association of the door handle and contamination of pathogenic bacteria. Door handles of clinical and research laboratories have higher chances of contamination with pathogenic bacteria during closing and opening with contaminated gloves on, or sometimes after visiting the toilets without the use of disinfectant materials. There is limited epidemiological data regarding bacteria cross contamination of door locks of the Clinical laboratory at Kilimanjaro Christian Medical Centre. This study aimed at providing the proportions of bacteria contaminating medical laboratory doors. Methods: A cross section laboratory-based study was conducted and it involved collection of swab samples from doors and working benches in the clinical laboratory. Results: Prevalence of Staphylococcus aureus, Escherichia coli, Coagulase Negative Staphylococcus, Bacillus spp., Pseudomonas aeroginosa and coliforms were (26%, 22%, 18%, 8%, 4% and 4% respectively. Conclusion: This study has reported high proportion of pathogenic bacteria. The results entails that, internal and external environments are responsible for laboratory door contamination.

Avian feathers as a biomonitoring tool to assess heavy metal pollution in a wildlife and bird sanctuary from a tropical coastal ecosystem.

In this study, we have assessed the concentrations of four heavy metals (Cu, Zn, Cd, and Pb) in the feathers of 11 species of birds from the Point Calimere Wildlife and Bird Sanctuary, a protected environment. Concentrations of copper and zinc were detected in all the bird species, cadmium was observed only in two bird species, and lead was below the detection limits for all birds. The order of concentration of metals in the feathers is Zn > Cu > Cd > Pb. Using the multivariate statistical analysis, principal component analysis (PCA), the metal origins were traced to natural, dietary, and manmade sources. In addition, sediment samples were also collected from the sanctuary, to assess the bioaccumulation factor (BAF). The BAF values follow the order Cd < Cu < Zn < Pb. In comparison with worldwide heavy metal reports in bird feathers, lower concentrations of metals are observed in our study area. The tropical marine ecosystem at Point Calimere Wildlife and Bird Sanctuary can be considered as pristine regarding heavy metal pollution. Continuous monitoring of the ecosystem is crucial to sustain the pristine nature of the sanctuary and to attract many more birds.

Health risk assessment and bioaccumulation of metals in brown and red seaweeds collected from a tropical marine biosphere reserve.

In the present study, we have assessed the degree of contamination of heavy metals (Cd, Cu, Pb, and Zn) in ten species of red and brown seaweeds, the seasonal variations in the concentration of metals, and the health risk due to the seaweeds. Overall metal concentrations for red and brown seaweeds followed the order Pb > Zn > Cu > Cd and Pb > Cu > Zn > Cd, respectively. Cd and Pb levels were found to be elevated in both the red and brown seaweeds. Multivariate statistical analysis revealed that the sources of Cd and Pb are mainly anthropogenic. Despite the high concentrations of the non-essential metals (Cd and Pb) in the seaweeds, the health risk assessment revealed that they have a lower hazard index. Hence, consumption of edible red and brown seaweeds from the Tuticorin coast may not pose health hazards in humans for the time being.

Rapport dÆenquête sur les paramètres socioéconomiques dans les communes de Petit Goâve, Grand Goâve et Jacmel, Haïti

L'étude a pour objectif de lancer la réflexion parmi les acteurs (bailleurs de fonds, responsables politiques, associatifsà) de la région sur l'importance de disposer d'outils et dÆanalyses socio-économiques dans les zones d'interventions et de transformer des paramètres économiques à large échelle vers un niveau plus tangible pour les familles et les autorités locales. Ce processus de vulgarisation des effets économiques dus aux catastrophes naturelles peut favoriser une prise de conscience majeure au niveau de base et un engagement majeur dans le domaine de la réduction des risques et des désastres des autorités locales