Fluoride risk assessment from agricultural soils in India: a study based on vertical, spatial and geochemical distribution.

Fluoride (F) in agricultural soil is increasing continuously due to injudicious application of F-laden fertilizers, causing global concern about fluorosis disease. The objective of the study was to assess F risk in humans due to soil ingestion, dermal contact, and particulate inhalation during various agricultural activities. The study also emphasized chemical fractionation, distribution, and geochemical understanding of high F incidence. Agricultural surface soil was sampled randomly from 5 km × 5 km square grids besides soil profile samples for studying the vertical distribution of F. Various F fractions in soil (1:1 soil:water ratio, calcium chloride extractable F, hot water soluble F, exchangeable F, Fe-Mn oxide bound F, organic matter bound F, residual F, and total F) were estimated using the sequential fractionation method. Multivariate geochemical analysis and soil F risk were also assessed in humans. The water soluble F (F1:1) and CaCl2 extractable F (FCa) varied between 0.11 to 6.73 mg kg-1 and 1.02 to 6.94 mg F kg-1 soil, respectively. Total fluoride (TF) however, ranged between 115 to 456 mg F kg-1. A higher average of FCa/TF moving down the soil profile indicated a propensity for F endemicity. Weathering, ion-exchange, alkalinity, and clay were found to control the soil geochemistry of the area. The F contamination index explained > 82% variance of F contamination, but the hazard quotient of F for an adult was found < 1, indicating no potential fluorosis risk in the area. This study is the first of its kind in India, where ecological risk due to F from agricultural soil was assessed in humans and will be a benchmark for future researchers.

Conservation Tillage and Waste Crop Residue Based Zinc Fortification in Rice and Wheat under Reclaimed Sodic Soils: Progress toward Nutrient Circularity and Sustainability.

Nearly 50% of the population across the globe is at risk of malnutrition with respect to zinc (Zn) in areas where a cereal based dietary system dominates. The present study estimated daily Zn intake in humans through field experiments in reclaimed sodic soil, utilizing waste crop residue (CR) in conservation tillage where CR played a vital role in enhancing Zn uptake in rice and wheat grains. Zn dynamics, its bioavailability, interaction with soil properties, and plausible contribution in dietary intake were studied extensively to supplement the research. A higher mobility factor (2.70%) and plant available Zn resulted in its higher uptake in rice (58.2 mg kg-1) and wheat (67.2 mg kg-1) under zero tillage in rice followed by zero tillage in wheat where CR was retained on the surface (ZTR-ZTW+CR). Daily Zn intake was found to be maximum (0.651 mg kg-1 day-1) under ZTR-ZTW+CR, demonstrating zinc sufficiency. Thus, this study may help in formulating actionable policies for combating both nutritional security and environmental hazards due to CR burning.

Identification of discriminating chemical compounds in banana species and their odor characterization using GC-MS, statistical, and clustering analysis.

The study aims identification of discriminating chemical constituents in the banana odor grown in Philippines and Ecuador using GC-MS characterization. Ester is recognized as a major chemical class in selected banana odor. Odors discriminating compounds like, 2-hexenal, ethyl acetate, and hexanoic acid, ethyl ester, etc. have been identified. Besides, other odors generating chemical compounds (alcohols, esters, aldehydes, and ketones) have been recognized. Furthermore, principal component analysis (PCA) and hierarchical cluster analysis were implemented to differentiate banana odors. PCA achieved 100% discrimination of selected bananas odors using the peak area information about recognizing chemical compounds. Odor identity and discrimination of selected bananas have been achieved successfully. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05298-9.

A gradient boosting machine learning approach in modeling the impact of temperature and humidity on the transmission rate of COVID-19 in India.

Meteorological parameters were crucial and effective factors in past infectious diseases, like influenza and severe acute respiratory syndrome (SARS), etc. The present study targets to explore the association between the coronavirus disease 2019 (COVID-19) transmission rates and meteorological parameters. For this purpose, the meteorological parameters and COVID-19 infection data from 28th March 2020 to 22nd April 2020 of different states of India have been compiled and used in the analysis. The gradient boosting model (GBM) has been implemented to explore the effect of the minimum temperature, maximum temperature, minimum humidity, and maximum humidity on the infection count of COVID-19. The optimal performance of the GBM model has been achieved after tuning its parameters. The GBM results in the best accuracy of R2 = 0.95 for prediction of active cases in Maharashtra, and R2 = 0.98 for prediction of recovered cases of COVID-19 in Kerala and Rajasthan, India.

Evaluating toxicity impacts of environmental exposed chromium on small Indian mongoose (Urva auropunctatus) hematological, biochemical and histopathological functioning.

Sub-lethal toxic impacts of chromium on hematological, biochemical and histological parameters were analyzed in the female small Indian mongoose (Urva auropuctatus) residing contaminated environment of tannery industry. Chromium bioaccumulation in the blood, liver and kidney tissue of the exposed mongooses was found elevated compared to the control mongooses' tissues. Total body weight (75.7%), liver weight (83.6%) as well as HSI (68.1%), RSI (86.2%) and the platelets counts (59.7%) were found significantly elevated, with significantly reduced RBCs (59.6%), and WBCs (64%). LFT and RFT were also found abnormal, moreover, the histopathological injuries had been distinct inside the kidney (>75%) and hepatic (>75%) tissues of exposed animals. Shrinkage and vacuolization (>75%) inside the hepatocyte expanded sinusoidal spaces and nuclear pyknosis (>75%) was evident within the hepatic tissue. Hypertrophy of epithelial cells of renal tubules and inter-renal cells of the head kidney with a reduction in tubular lumens (>75%) and vacuolization of tubules were witnessed within the kidney section. Atrophy inside the kidney inter-renal cells, glomeruli compression within the Bowman's capsules (>75%) following the necrosis in hematopoietic tissues were found in exposed animals. The present findings indicate that chronic exposure to chromium induces severe anemia, decreased serum protein concentration, hepatic and renal tissue histopathology, impairing the vital capabilities of liver, metabolic regulation, excretion, and stress homeostasis maintenance of which within the long-run may posture a severe risk to animal well-being then distress their inhabitants.

Human health damages related to air pollution in China.

In recent years, air pollution in China has posed serious threats to human health. In this study, we investigate the relationship between air pollution and residents' health by nesting the household registration data of the China Migrant Dynamic Survey in 2014 with city characteristic data and pollution data. The results indicated that an increase in the concentration of air pollution significantly reduced residents' health levels. After using the instrumental variable (IV)-Oprobit model to solve endogenous problem, we have found that the negative impact of air pollution on residents' health remained significant. Moreover, the lag term of environmental indexes was introduced and found that air pollution significantly increased health risk. The results also demonstrated that the impact of air pollution on human health was heterogeneous. Men and urban residents were more sensitive to air pollution and more adversely affected. In addition to air pollution, the study found that, among the influencing factors at the individual level, males' health was better than females' health, and education positively impacted on residents' health. The health effects were consistent with the theoretical predictions of the Grossman model. The financial expenditure and medical input were negatively correlated with residents' health levels. Based on the results, we suggest the Chinese government should implement rigorous air pollution laws and regulations.

Olfaction-inspired sensing using a sensor system with molecular recognition and optimal classification ability for comprehensive detection of gases.

In this study, we examined the comprehensive detection of numerous volatile molecules based on the olfactory information constructed by using olfaction-inspired sensor technology. The sensor system can simultaneously detect multiple odors by the separation and condensation ability of molecularly imprinted filtering adsorbents (MIFAs), where a MIP filter with a molecular sieve was deposited on a polydimethylsiloxane (PDMS) substrate. The adsorption properties of MIFAs were evaluated using the solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). The results demonstrated that the system embedded with MIFAs possesses high sensitivity and specific selectivity. The digitization and comprehensive classification of odors were accomplished by using artificial odor maps constructed through this system.

Fluoride in the environment and its metabolism in humans.

The presence of environmental fluoride and its impact on human health is well documented. When consumed in adequate quantity, fluoride prevents dental caries, assists in the formation of dental enamels, and prevents deficiencies in bone mineralization. At excessive exposure levels, ingestion of fluoride causes dental fluorosis skeletal fluorosis, and manifestations such as gastrointestinal, neurological, and urinary problems. The distribution of fluoride in the environment is uneven and largely is believed to derive from geogenic causes. The natural sources of fluoride are fluorite, fluorapatite, and cryolite, whereas anthropogenic sources include coal burning, oil refining, steel production, brick-making industries, and phosphatic fertilizer plants, among others. Among the various sources of fluoride in the environment, those of anthropogenic origin have occasionally been considered to be major ones. The gourndwater is more susceptible to fluoride accumulation and contamination than are other environmental media, primarily because of its contact with geological substrates underneath. The high fluoride concentration in water usually reflects the solubility of fluoride (CaF2). High concentrations are also often associated with soft, alkaline, and calcium-deficient waters. The fluoride compounds that occur naturally in drinking water are almost totally bioavailable (90%) and are completely absorbed from the gastrointestinal tract. As a result, drinking water is considered to be the potential source of fluoride that causes fluorosis. Because the bioavailability of fluoride is generally reduced in humans when consumed with milk or a calcium-rich diet, it is highly recommended that the inhabitants of fluoride-contaminated areas should incorporate calcium-rich foods in their routine diet. Guidelines for limiting the fluoride intake from drinking water have been postulated by various authorities. Such limits are designed to protect public health and should reflect all fluoride intake sources, including dietary fluoride. The toxicological risks posed by fluoride could be better understood if epidemiological surveillance for dental and skeletal fluorosis would be systematically conducted in fluoride-affected areas. Such input would greatly improve understanding of the human dose-response relationship. Such surveillance of potentially high fluoride areas is also important because it would help to delineate, much earlier, the remedial measures that are appropriate for those areas.

Quality control of herbal medicines by using spectroscopic techniques and multivariate statistical analysis.

Herbal medicines play an important role in modern human life and have significant effects on treating diseases; however, the quality and safety of these herbal products has now become a serious issue due to increasing pollution in air, water, soil, etc. The present study proposes Fourier transform infrared spectroscopy (FTIR) along with the statistical method principal component analysis (PCA) to identify and discriminate herbal medicines for quality control. Herbal plants have been characterized using FTIR spectroscopy. Characteristic peaks (strong and weak) have been marked for each herbal sample in the fingerprint region (400-2000 cm(-1)). The ratio of the areas of any two marked characteristic peaks was found to be nearly consistent for the same plant from different regions, and thus the present idea suggests an additional discrimination method for herbal medicines. PCA clusters herbal medicines into different groups, clearly showing that this method can adequately discriminate different herbal medicines using FTIR data. Toxic metal contents (Cd, Pb, Cr, and As) have been determined and the results compared with the higher permissible daily intake limit of heavy metals proposed by the World Health Organization (WHO).