Health impacts of chemical pesticides: The perspective of vegetable farmers

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Spatial Distribution of Fluoride in Drinking Water in Dhamar City, Yemen

The fact that groundwater is the only source of drinking water in Yemen mandates strict monitoring of its quality. The aim of this study was to measure the levels of fluoride in the groundwater resources of Dhamar city. Dhamar city is the capital of Dhamar governorate located in the central plateau of Yemen. For this purpose, fluoride content in the groundwater from 16 wells located around Dhamar city was measured. The results showed that 75% of the investigated wells contain fluoride at or below the permissible level set by the World Health Organization (0.5 – 1.5 mg/L), whereas 25% of the wells have relatively higher fluoride concentrations (1.59 – 184 mg/L). The high levels of fluoride have been attributed to the anthropogenic activities in the residential areas near the contaminated wells. Interestingly, some wells contain very low fluoride concentrations (0.30 – 0.50 mg/L). Data were statistically treated using the principal component analysis (PCA) method to investigate any possible correlations between various factors. PCA shows a high correlation between well depth and its content of fluoride. On the other hand, health problems dominating in the study area necessitate further studies to investigate any correlation with imbalanced fluoride intake.

Daily Climate Extremes of Temperature and Precipitation Over Quetta Valley, Pakistan During 1961-2019

Climate extremes are imperative to study the impacts of climate change that is significantly observed for the management of scarce water resources of the Quetta Valley. The daily data of temperature and precipitation are used to model the climate extreme indices for Quetta Meteorological Station from1961 to 2019. The statistical tests were performed by using Mann Kendal and Sen’s Slope method at the 95% confidence level. The overall change in minimum to maximum temperatures and precipitation-based climate extreme indices specify the frequencies of extreme events are increasing. That would cause heatwaves, gradual warming, steady dryness, and extreme precipitation events in the long term over the Quetta Valley. The minimum and maximum temperature-based indices inclusively indicate positive trends. That ultimately leads to a warming climate with a significant increase in summer as 5 days/decade, tropical nights as 5.3 days/decade, daily maximum as 0.28°C/decade, warm nights as 1.7 days/decade and warm days as 1.9 days/decade. For precipitation, all the indices show positive trends with a significant increase in consecutive wet days for 0.1 days/decade and an annual contribution of very wet days 0.8% per decade. The monthly increase in temperature and decrease in precipitation would increase the evaporative demands which may arise the water stress conditions over the valley and may put pressure over groundwater reservoirs.

Water Beetles: Species Diversity and Response to Physico-Chemical Parameters in Different Freshwater Habitats in Samtse, Bhutan

Bhutan is located between the two zoogeographic regions which are assumed to be rich in diversity of water beetles. The study aimed to determine the diversity and distribution pattern of water beetles in different freshwater habitats in Namgaychholing under Samtse district, Bhutan. The study also analysed the association of water beetles with the physico-chemical parameters. The data were collected from four different habitats with sample plot of 3 m × 1 m for a standard time of 1 hour in every plot. A total of 30 species belonging to 7 families were recorded of which Dytiscidae (n=626, RA=51) was the most abundant family and Lacconectus basalis (n=416, RA=34.13) was the most abundant species. The overall Shannon diversity index of the study area was H ′=2.48. Amongst the different habitats, marshy area had the highest Shannon diversity index (H ′=2.45) and stream had the lowest (H ′=1.82). A Kruskal Wallis test on diversity among different habitats showed no significant difference (p<.05). Through a cluster analysis, the species composition between the river and waterlogged showed 100% similarity index. Canonical correspondence analysis showed temperature as a main determining factor affecting the distribution of water beetles. With broad families encompassing the water beetles, similar study on water beetles in different regions of the country is recommended with particular emphasis on different families. Moreover, Bhutan falls in junction of Palearctic and Oriental Zoogeographic regions, which are known to be rich in diversity of water beetles. Hence, study in high-altitude lakes, which are assumed to be rich in diversity of water beetles are recommended despite social beliefs to keep lakes isolated and undisturbed.

Evaluation of Contamination and Accumulation of Heavy Metals in the Dhaleswari River Sediments, Bangladesh

The Dhaleswari river is considered as one of the most important rivers of Bangladesh due to its geographical location and ecological services. The present study attempts to evaluate the degree of heavy metal pollution, contamination, and accumulative behavior in the sediment of the Dhaleswari river. The sediment samples were collected from fifteen different locations of the Dhaleswari river. Heavy metals were analyzed using the Flame Atomic Spectrophotometer (FAAS). The mean concentrations of Zn, Cu, Cr, Pb and Cd were 131.9, 48.89, 43.16, 33.23 and 0.37 mgkg-1, respectively. According to the United States Environmental Protection Agency (USEPA) Sediment Quality Guideline, the sediment of most of the locations were not polluted for Pb and Cd. But S-11 location for Cd (0.8 mg kg-1) was highly polluted. For Cr, Cu and Zn, maximum locations were moderately polluted. Although the geo-accumulation index (Igeo) values of Dhaleswari river sediments showed almost no severe contamination for most of the sampling locations, the pollution load index (PLI) values showed that most of the sampling sites were contaminated for all heavy metals tested. Moreover, for all measured heavy metals, the mean Contamination Factor (CF) values indicated moderate pollution, except for Cr, which suggested low pollution. The Pearson’s correlation coefficient matrix among the selected heavy metals of Dhaleswari river sediment showed no significant correlation among each other. Therefore, regular monitoring of the heavy metal concentration of the Dhaleshwari river sediment from different location is necessary to identify the sources of pollution so that proper initiative could be taken to prevent heavy metal pollution.

Temporal Variability of Soil Reaction Among Surface and Near-Surface Horizons of Soils of Dissimilar Lithology in a Humid Tropical Environment

The study investigated changes in soil reaction among surface and near surface horizons of four soil groups as affected by wet and dry seasons in Southeastern Nigeria. A geological map of the area guided soil sampling. Free survey approach was used in locating soil profiles. Soil samples were collected based on horizon differentiation and samples were collected from the AB-horizon (near-surface) and the A-horizon (Surface). Routine laboratory analyses were conducted on these soil samples after sieving through a 2-mm sieve. Data were subjected to analysis of variance (ANOVA) using SAS Statistical Computer Package. There were significant (p<0.05) changes in soil reaction in A- and AB-horizons in the dry seasons of 2016 and 2017. Similarly, in the wet season, soil pH varied significantly (p<0.05) in 2016 and 2017. Soil reaction significantly (p<0.05) differed in AB-horizons in both 2016 and 2017 irrespective of the season. All soil samples were acidic irrespective of lithologic material and season with pH values ranging from 4.20-5.60 and 3.31-5.42 in the A- and AB-horizons, respectively.

Status and Role of Medicinal and Aromatic Plants (MAPs) in Nepalese Livelihood

Medicinal and aromatic plants (MAPs), a principal sub-component of Non-Timber Forest Products (NTFPs), are undoubtedly an important source of revenue and rural employment. This review paper explores the current ecological and prioritized status of MAPs by the Government and the practical significance of MAPs in bodily health, lucrative employment to the Nepalese population, and revenue opportunities to the government based on 72 published articles from 1995 to 2021. The Department of Plant Resources (DPR) reported that the number of medicinal plant species has increased from 701 in 2007 to 819 in 2016 with 285 endemic plant species from 43 families, and 238 chemically tested MAPs species for medicinal significance. MAPs are highly prevalent within the 1000-2500m elevation gradient in Nepal. GoN has categorized 30 species for economic development, 12 species for cultivation and research, 12 species for protection, and 237 species for collecting royalties. Around 100 Nepalese NTFPs/MAPs are traded, but only 20 species accounts for 80% of the total trade in terms of volume and value. Nepal ranks 42nd with a value of $7.4 million and 62nd with a value of $3.3 million in exports of MAPs and essential oils, respectively, in 2017. About 80% of the Nepalese population relies on traditional medicine for basic health needs. The NTFPs/MAPs Business Promotion Strategy specifies 20 species for product promotion across Nepal. As current data are still lacking on different uses of MAPs in Nepalese society, this comprehensive review will facilitate herbal specialists, policymakers, scientific researchers, botanists, and various key stakeholders to assure better research and increase the export of MAPs in Nepal. Therefore, this study recommends public, private, and government- agencies to contribute to the infrastructure development through competitive "field-to-market" incentives and funding for the increment of the export of MAPs that directly improve the socio-economic status of the Nepalese people.

Water Quality Modelling of River Mahanadi using Principal Component Analysis (PCA) and Multiple Linear Regression (MLR)

Surface water quality is one of the critical environmental concerns of the globe and water quality management is top priority worldwide. In India, River water quality has considerably deteriorated over the years and there is an urgent need for improving the surface water quality. The present study aims at use of multivariate statistical approaches for interpretation of water quality data of Mahanadi River in India. Monthly water quality data pertaining to 16 parameters collected from 12 sampling locations on the river by Central Water Commission (CWC) and Central Pollution Control Board (CPCB) is used for the study. Cluster analysis (CA), is used to group the sampling locations on the river into homogeneous clusters with similar behaviour. Principal component analysis (PCA) is quite effective in identifying the critical parameters for describing the water quality of the river in dry and monsoon seasons. PCA and Factor Analysis (FA) was effective in explaining 69 and 66% of the total cumulative variance in the water quality if dry and wet seasons respectively. Industrial and domestic wastewaters, soil erosion and weathering, soil leaching organic pollution and natural pollution were identified as critical sources contribution to pollution of river water. However, the quantitative contributions were variable based on the season. Results of multiple linear regression (MLR) are effective in explaining the factor loadings and source contributions for most water quality parameters. The study results indicate suitability of multivariate statistical approaches to design and plan sampling and sampling programs for controlling water quality management programs in river basins.

Diversity, Distribution and Morphology of Wild Mushrooms Collected from Gajni Forest of Bangladesh

A survey was carried out in Gajni forest from June to August of 2017 and 2018 to document the diversity, distribution and morphological characterization of wild mushrooms. A total of 32 mushroom samples were collected and identified to 28 species belonging to 11 genera, under 8 families. Ganoderma sp. was found abundantly in the survey area among the other collected species and it exhibited the maximum frequency of occurrence (75%), whereas the maximum density (20.50%) was recorded for Agaricus bitorquis and the dominant host was Shal tree (Shorea robusta). The dominant genera were Ganoderma, Agaricus, Trametes, Volvariella and Amanita. The dominant family of collected wild mushrooms was Ganodermataceae followed by Polyporaceae, Agaricaceae, Amanitaceae, Rusullaceae, Pluteaceae, Marasmiaceae and Strophariaceae. Among collected species, 5 species were found edible, 12 species had medicinal value and 11 species were inedible, poisonous or of unknown importance. The specimens were deposited to the Sher-e-Bangla Agricultural University Herbarium of Macro Fungi (SHMF). This is a report of wild mushrooms diversity and their distribution in the Gajni forest region of Bangladesh. This study was asserted that a wide range of mushroom plays an important role in the ecosystem of Gajni forest and might be useful in food and industry sector in future.