Ibuprofen (IBU), as a commonly used non-steroidal anti-inflammatory drug (NSAID) and pharmaceutical and personal care product (PPCP), is frequently prescribed by doctors to relieve pain. It is widely released into environmental water and soil in the form of chiral enantiomers by the urination and defecation of humans or animals and by sewage discharge from wastewater treatment plants. This study focused on the alteration of metabolism in the adult zebrafish (Danio rerio) brain after exposure to R-(-)-/S-(+)-/rac-IBU at 5 μg L−1 for 28 days. A total of 45 potential biomarkers and related pathways, including amino acids and their derivatives, purine and its derivatives, nucleotides and other metabolites, were observed with untargeted metabolomics. To validate the metabolic disorders induced by IBU, 22 amino acids and 3 antioxidant enzymes were selected to be quantitated and determined using targeted metabolomics and enzyme assay. Stereoselective changes were observed in the 45 identified biomarkers from the untargeted metabolomics analysis. The 22 amino acids quantitated in targeted metabolomics and 3 antioxidant enzymes determined in enzyme assay also showed stereoselective changes after R-(-)-/S-(+)-/rac-IBU exposure. Results showed that even at a low concentration of R-(-)-/S-(+)-/rac-IBU, disorders in metabolism and antioxidant defense systems were still induced with stereoselectivity. Our study may enable a better understanding of the risks of chiral PPCPs in aquatic organisms in the environment.

Copper (Cu) is an essential yet potentially toxic metal, thus delicate homeostatic controls are developed in the fish. In this study, a physiologically based pharmacokinetic (PBPK) model was developed to simulate the homeostatic regulation of Cu in a marine fish (Terapon jarbua) under dietary and waterborne exposures. In this model, fish were schematized as a six-compartment model, with the intestine being divided into two sub-compartments (chyme and gut wall). The blood was assumed to be the “carrier” distributing Cu into different compartments. The transfer rates between different compartments were determined in fish during Cu exposure (20 d) and depuration (20 d). The differences in Cu transfer from chyme to gut wall between dietary and waterborne treatments suggested that the intestine regulated the dietary uptake and re-absorption of Cu from the chyme. The extremely low uptake rate constant (0.0013 d−1) for gills under waterborne exposure indicated that gills strongly restricted Cu uptake from the ambient water. For both treatments, the liver had considerable input rate through the enterohepatic circulation and comparably high exchange rate with the blood, suggesting that the liver can efficiently accumulate newly absorbed Cu. The differences in Cu output from the liver between dietary and waterborne treatments suggested that it can effectively regulate the redistribution of Cu. All of these observations demonstrated that the liver played the central role in Cu homeostasis by serving as the main depository and distributing center. Modeling results also indicated that renal and branchial excretion was of minor importance, whereas biliary excretion combined with defecation played the most important role in whole-body Cu elimination in marine fish. The effective regulation by the “Blood-Liver-Intestine” cycle could be the main reason for the relatively low levels of Cu in fish.

Di(2-ethylhexyl)phthalate (DEHP) is an ubiquitous and emerging contaminant that is widely present in food, agricultural crop, and the environment, posing a potential risk to human health. This study utilized the nematode Caenorhabditis elegans to decipher the toxic effects of early life exposure to DEHP on aging and its underlying mechanisms. The results showed that exposure to DEHP at 0.1 and 1.5 mg/L inhibited locomotive behaviors. In addition, DEHP exposure significantly shortened the mean lifespan of the worms and further adversely affected pharyngeal pumping rate and defecation cycle in aged worms. Moreover, DEHP exposure also further enhanced accumulation of age-related biomarkers including lipofuscin, lipid peroxidation, and intracellular reactive oxygen species in aged worms. In addition, exposure to DEHP significantly suppressed gene expression of hsp-16.1, hsp-16.49, and hsp-70 in aged worms. Further evidences showed that mutation of genes involved in insulin/IGF-1-like signaling (IIS) pathway (daf-2, age-1, pdk-1, akt-1, akt-2, and daf-16) restored lipid peroxidation accumulation upon DEHP exposure in aged worms, whereas skn-1 mutation resulted in enhanced lipid peroxidation accumulation. Therefore, IIS and SKN-1 may serve as an important molecular basis for DEHP-induced age-related declines in C. elegans. Since IIS and SKN-1 are highly conserved among species, the age-related declines caused by DEHP exposure may not be exclusive in C. elegans, leading to adverse human health consequences due to widespread and persistent DEHP contamination in the environment.

Despite of their ubiquitous distribution in marine sediments, the role of benthic fauna in microplastic transport at the sea floor has received little attention yet. The present study investigated the influence of bioturbation activity of the polychaete Arenicola marina on microplastic transport and burial in marine sediments. Sediment ingestion was assessed in a long term mesocosm experiment with exposure times ranging from 106 to 240 days, using three particle tracers with different particle diameters (microplastic: 500 and 1000 μm, respectively; luminophores: 130 μm). Sediment grain size distributions were assessed after experiment termination in all feeding layers at 8–12 cm depth to determine the influence of size-selective feeding of A. marina on median grain size and microplastic retention. Burial of microplastic occurred in all mesocosms up to a depth of 20 cm and was strongly dependent on individual sediment feeding rates. For low bioturbation conditions, both microplastic and luminophore concentrations exhibited an exponential decrease with increasing sediment depth, indicating particle burial via feeding funnel transport. Particle concentrations remained high in the uppermost 4 cm of the sediment. At high bioturbation rates, no microplastic particles remained in near-surface sediment layers, but a distinct accumulation of microplastic was observed in the feeding layer, suggesting the discrimination of plastic particles during feeding. In contrast, luminophores displayed a similar accumulation, but additionally showed uniform distributions above feeding layers, indicating ingestion and defecation by polychaetes. In accordance with these findings, an overall coarsening of median grain sizes was observed in all feeding layers, indicating the retention of large microplastic due to size-selective feeding. These findings demonstrate the ability of the conveyor belt-feeding polychaete A. marina to promote unidirectional transports of microplastic ≥500 μm and the potential for the long-term retention of these particles in marine sediments.

Many people practice open defecation in south Asia. As a result, lot of human waste containing nutrients such as nitrogen (N) and phosphorus (P) enter rivers. Rivers transport these nutrients to coastal waters, resulting in marine pollution. This source of nutrient pollution is, however, ignored in many nutrient models. We quantify nutrient export by large rivers to coastal seas of Bangladesh, India and Pakistan, and the associated eutrophication potential in 2000 and 2050. Our new estimates for N and P inputs from human waste are one to two orders of magnitude higher than earlier model calculations. This leads to higher river export of nutrients to coastal seas, increasing the risk of coastal eutrophication potential (ICEP). The newly calculated future ICEP, for instance, Godavori river is 3 times higher than according to earlier studies. Our modeling approach is simple and transparent and can easily be applied to other data-poor basins.

While the state of sanitation in Pakistan has improved in the last decade, a significant proportion of its population is still using inadequate sanitation or no toilet facility at all. Open defecation has decreased over the years; however, it has been replaced by poor quality sanitation in rural areas that might still cause diarrhoea and undernutrition. The research regarding inadequate sanitation in Pakistan, especially in terms of the sanitation ladder, remains limited. The present research thus fills this research gap by assessing the impact of different types of sanitation on the prevalence of stunting and underweight (moderate as well as severe) among under-five children in Pakistan using the nationally representative micro survey, Pakistan Demographic and Health Survey (2017-18). The sanitation ladder comprises of piped to sewer (highest level, base) followed by flush to septic tank, flush to pit latrine, other improved, unimproved sanitation, and open defecation. In order to estimate the adjusted and unadjusted odds ratios of the determinants, this research uses logistic regressions are used to estimate adjusted and unadjusted odds ratios of the determinants. We show that toilets connected to piped sewerage network are rare in the rural areas of Pakistan and a large segment of the rural population is still practicing open defecation. The logistic regressions show that piped sewerage network and flush to septic tanks are associated with lowest odds (both adjusted and unadjusted) of stunting and underweight among under-five children. In multivariate regressions, pit latrines are associated with even higher adjusted odds of severe and moderate and severe stunting as well as underweight among under-five children, showing that poor quality pit latrines may bring the source of faecal contamination to the doorstep of the households. Therefore, interventions targeting reduction in open defecation should promote good quality toilets for sustainable long-term improvements in child health.

The Swachh Bharat Mission undertaken by the Government of India (GoI) has been successful in accomplishing this objective within a short period thereby catalyzing governance following Sustainable Development Goals (SDGs). It is the responsibility of any democratic nation to ensure that its citizens have universal access to adequate and equitable sanitation. The key approach adapted to igniting a change in sanitation behavior rather than constructing toilets. An effort has been made in the study to affirm that even the marginalized sections of the society residing in tribal communities of West Bengal and Chhattisgarh have benefitted from this Government of India Mission and derived the required benefits. There is enough literature available to support the justification that civil participation holds the key for successful implementation of CLTS thereby making the communities open defecation free (ODF). It is therefore imperative to understand the behavioral transformation that takes place during the CLTS implementation. A hybrid model has been proposed in the study making use of the theory of reasoned action (TRA) and theory of planned behavior (TPB) to understand the pre-adoption and post-adoption behavior of residents. In present study, used model was empirically tested for several hypotheses. The finding reflects towards subjective norms and facilitating conditions as major determinants that ensure the continuation of intention for CLTS. They play a pivotal role in improving the health and hygiene conditions in the region and thus decrease the risk of spread of epidemic diseases.

This study aims to investigate the effects of air quality on child mortality in developing countries. We consider annual data covering the period from 2010 to 2016 of 58 countries and estimate the empirical models using recently developed panel quantile regression with the method of moments (MM-QR). It is found that outdoor air quality (measured by the concentration of PM₂.₅ in the air) has a positive and significant effect on total child mortality, post-neonatal mortality, and under-five child mortality. However, its effect on neonatal mortality is not statistically significant at lower quantiles. Furthermore, Household air pollution (HAP) also has a positive and significant effect on total child mortality, neonatal mortality, and under-five child mortality. The effect of HAP on post-neonatal mortality is not significant in most cases. Overall, the adverse effect of HAP is larger than the PM₂.₅. For instance, a 1% increase of PM₂.₅ concentration in the outdoor causes 0.231% total child mortality due to respiratory diseases at [Formula: see text], while a 1% increase of HAP causes 0.532% total child mortality at the same quantile. In many cases, the coefficients of PM₂.₅ and HAP increase at the higher quantiles, supporting asymmetric effects of pollutants on child mortality. However, per capita income, access to basic drinking water and sanitation facilities, and domestic and external health expenditures significantly reduce child mortality. On the contrary, open defecation increases mortality. Consequently, policymakers should take adequate measures to improve indoor and outdoor air quality to combat child mortality due to respiratory diseases in developing countries. They should also take initiatives to enhance per capita income, basic drinking water, and sanitation facilities, domestic and external health expenditures, and public awareness against open defecation.

With the growing awareness of the linkage among open defecation (OD), environment, and health, it is important to understand the factors responsible for OD. It is a necessary step toward developing a strategy to end open defecation for ensuring a better environment and human health. There is no such study available for Pakistan. The study, therefore, aims to bridge this gap. Using household data of Pakistan Demographic and Health Survey (PDHS) 2017–2018, an association of OD with potential predictors, analysis of variance, and a logistic regression model are employed to develop the evidence. The results suggest that place of residence, education, poverty status, social norms, geopolitical regions, and living space significantly predict the OD behavior in Pakistan. This study recommends two things: first is to facilitate the households and communities to own latrines, second is to change the behavior through intervention. However, political commitment and effective administration will be key to ascertain ending OD.

Golinga reservoir provides water for drinking and domestic and agricultural activities for its surrounding communities. However, competitive demand and multiple-use necessitated a study into the influence of the multipurpose use on the water quality and subsequent health risks. The 6-month research employed observations and water sampling to assess the impact. Empirical orthogonal function, analysis of variance, and variance–covariance were run to interpret the obtained data. The study recorded ranges for pH (6.65–7.11 pH units), turbidity (3.33–80.66 NTU), conductivity (67.73–191.93), nitrate-nitrogen (0.13–6.17 mg/L), PO₄-P (0.01–0.08 mg/L), sulphate (0.05–0.09 mg/L), fluoride (0.12–0.32 mg/L), sodium (4.67–15.46 mg/L), potassium (2.20–3.75 mg/L), faecal coliform (log₁₀ 1.30–log₁₀ 2.56 cfu/100 mL), E. coli (log₁₀ 0.77–log₁₀ 1.23 cfu/100 mL), and Salmonella spp. (log₁₀ 1.51–log₁₀ 1.62 cfu/100 mL). All except turbidity fell within acceptable levels. Pairing the physical and chemical parameters showed a significant relationship (p < 0.05) except for pH and Na⁺, SO₄²⁻, K⁺ and F⁻, Na⁺ and K⁺, and F⁻, and K⁺ and F⁻, and SO₄²⁻ and F⁻ and SO₄²⁻ which revealed no significance (p > 0.05). Pairing the bacteria loads was presented a significant association (p < 0.05) except for faecal coliform and Salmonella spp. which were not significant (p > 0.05). Frequent activities were noted to support the revelation of high faecal contamination. The research suggests community by-laws enforcement curtail cattle movement as well as adequate disinfection methods to render the water suitable for potable use. The presence of pathogenic bacteria was attributed to open defaecation which poses negative health effects such as gastroenteritis, especially when water is orally consumed without prior treatment. Open defaecation was noted and supports the detection of high faecal contamination. The research suggests the promotion of simpler disinfection methods to render the water potable, enforcement of community by-laws, and in-depth environmental quality monitoring.