Due to the importance of climatic variability, an assessment detecting the changes and trends has been carried out over different time series of major climatic variables from the records of meteorological stations over Bangladesh from 1988-2017. Linear regression, the Mann-Kendall test, and Sen's slope method were used to analyze the significant trends and magnitude of the variables' changes, while the Pearson and Spearman rho correlation test have been applied to correlate between the variables. The results show that the average monthly maximum temperature (T max ) and minimum temperature (T min ) have increased significantly by 0.35 °C/decade and 0.16 °C/decade, respectively. However, the increase in T max is comparatively higher than T min and caused significant increases in the monthly temperature range (MTR) at a higher rate in winter than in the monsoon season. The trend patterns of T max , T min , and MTR reveal that most of the regions of the country (especially the south-eastern and north-eastern) have been colder during winter and hotter during the monsoon. In contrast, the wind speed (WS) has decreased significantly all over the country and decreased by a higher rate in the north-western (NW) region (monsoon, 0.60 and annual, 0.51 kt/decade) than other regions, while the monsoonal and annual precipitation have decreased by 87.35 mm/decade and 107 mm/decade, respectively. The monsoonal T max and T min (0.47 °C/decade and 0.38 °C/decade, respectively) have increased significantly in the NW; consequently, this region has been warmed by 0.27 °C/decade. The increase in temperature and decrease in WS may cause a decrease in rainfall in the NW region. Humidity changes are not significant except in the monsoon season across the country. Precipitation, WS, and humidity are negatively correlated with the temperature variables. The declination of WS may influence the rising trend in temperature and the falling trend in precipitation and humidity, suggesting the need for further advanced study on the negative effects of climate change in Bangladesh.

Lead (Pb) is a widely occurring heavy metal employed in industrial products and hence released into the environment, causing several environmental health risk concerns. This study comprehensively surveyed the literature on Pb contamination in different agricultural foods and food products commonly consumed by Bangladeshi inhabitants and assessed associated cancer and non-cancer health risks. Cereals (i.e., rice, wheat and maize) contained very high concentrations of Pb among the selected food items, the highest was found in wheat (4.04 µg g⁻¹), while rice and maize were 2.22 and 1.43 µg g⁻¹, respectively, that exceeded the maximum allowable concentration (MAC, 0.20 µg g⁻¹) for cereals. Vegetables contained higher Pb than the MAC of 0.01 µg g⁻¹, except for mushroom, green banana, cauliflower and arum. In addition, pulses also contained a moderate amount of Pb; however, fruits contained a low level of Pb, except for mangoes. When examining spatial differences in Pb contamination, most districts exhibited high Pb content in cereals; however, vegetables of the Tangail district exhibited the highest Pb concentrations (2.17 µg g⁻¹), originating from industrial operations and vehicular emissions. In terms of human health risk assessment, it was observed that consumption of rice, zucchini, tesla gourd, sponge gourd, okra, drumstick lib, chili and cabbage might pose non-cancer health risks (THQs > 1); however, fruits and pulses do not pose any non-cancer health risks to Bangladeshi residents. Most of the cereals and vegetables showed a higher value than 10⁻⁶, indicating a potential cancer risk; however, fruits and pulses showed lower risk only marginally exceeding the lower allowable limit (i.e., 10⁻⁶). Graphical abstract

In order to evaluate the heavy metals contamination of groundwater in Barapukuria Coal Mine (BCM) area and its vicinity, nine groundwater samples from different location, two waste water either treated and/or untreated that were used to irrigate in and around the coal mine areas, three surficial soil samples (~20cm depth) and a coal dust sample were collected during March, 2015. The samples were analyzed by inductively coupled plasma mass spectrometry (ICP–MS). Each sample was analyzed for As, Mn, Fe^total, Cu, Pb, Zn, Mo, Ni, Co, Cr, Cd and Hg. It was found that As, Cu, Pb, Zn, Mo, Co, Cr, Cd and Hg did not exhibit significant elevated levels, but concentration of Mn, Fe^total and Ni ranging from 0.15 to 3.85mg/L, 0 to 1.88mg/L and 0.01 to 0.09mg/L respectively both in groundwater and mine waste water samples exceeded the World Health Organization (WHO, 2004) drinking water guideline values of 0.4mg/L of Mn, 0.3 mg/L of Fe and of 0.02mg/L of Ni. Similarly the mean heavy metal concentrations in soils were below the Bangladesh standards for all heavy metals but the maximum values of Co (137.25 to 245.24mg/kg), Cr (139.02 to 243.38mg/kg) and Hg (0 to 24.28mg/kg) also exceeded the maximum acceptable limit of Food and Agricultural Organization (FAO, 1992) (Co of 50mg/kg, Cr of 100mg/kg) and Environment Agency (EA, 2009) (Hg of 1mg/kg) guideline standard. However, the coal dust was not above the guideline recommended limit for any elements. Therefore, this study reveals that the use of treated and/or untreated coal mine waste water for irrigation has increased the risk of heavy metals contamination in groundwater and causing potential health hazards in the long time term.