Physicochemical Analysis of Surface Water in Rohri Canal from Sukkur Barrage to Mehrabpur

The purpose of this study was to assess the effect of domestic and industrial waste discharge on the surface water quality of Rohri Canal in the stretch of the canal from Sukkur Barrage to Mehrabpur town. Eight sampling points were selected along the canal focusing on canal locations near major settlements. The parameters studied were temperature, pH, turbidity, hardness, alkalinity, total dissolved solids and suspended solids, chlorides, biochemical oxygen demand (BOD), chemical oxygen demand (COD) and E-coli. The average value of BOD and COD at the sampling stations were recorded as 212 mg/L and 423 mg/L respectively, which exceed the permissible surface water limits for drinking and irrigation purposes. The results indicate significantly higher value of BOD in sampling locations where there are major settlements and there is a continuous inflow of untreated sewage into the canal. The pH values at all the sampling sites were found within the drinking and irrigation water quality standards whereas the TDS values at only sampling stations (3 and 4) exceeded these limits. The turbidity values of the samples ranged from 237 to 821 NTU, exceeding the WHO drinking water quality standards for this parameter. The values of the water quality parameters including hardness (range 146 to 300 mg/L), chlorides (range 36 to 103 mg/L) and alkalinity (range 120 to 230 mg/L) were found well below the limits of WHO drinking water quality standards. The turbidity values of the samples ranged from 237 to 821 NTU and exceeded the WHO drinking water quality standards for this parameter. At all the sampling sites located near major settlements low levels of dissolved oxygen and the presence of E.coli were recorded. The results revealed that the continuous inflowing of untreated or un-treated sewage and industrial effluents into the canal has changed its physicochemical and biological characteristics, which make it unfit for human consumption and can have long-term irrevocable ecological threats if left unmanage

Organohalogenated contaminants (OHCs) in high-altitude environments:A review and implication for a black carbon relationship

Organohalogens contain important groups of persistent organic pollutants that have a special focus owing to their adverse effects. Due to long-range atmospheric transport, these chemicals could reach to higher altitude cold regions where they become deposited and trapped on surface media, i.e., soil, water, sediments, and snow. Intriguingly, another pollutant, black carbon (BC) shows a strong association with these organohalogens and could sturdily affect the environmental distribution of these contaminants. It is implicated that BC can significantly alter not only the behavior of organohalogens in the environment but its presence could also lead to an increase in temperature which may result in the rerelease of the trapped organohalogens in these regions. Hence, theories of “glacier hypothesis” and “forest filter effect” could be better explained

Role of black carbon in soil distribution of organochlorines in Lesser Himalayan Region of Pakistan

Black carbon and total organic carbon (TOC) along with organochlorines (OCs) were analyzed in soils from four sampling zones of Lesser Himalayan Region based on source proximity/anthropogenic influences along the altitude. CTO-375 method was used for BC analysis while OCs were analyzed by GC-MS/MS system. BC and TOC ranged between 0.16–1.77 and 6.8–41.3 mg g−1 while those of OCPs and PCBs ranged between 0.69 and 5.77 and 0.12–2.55 ng g−1, respectively. ∑DDTs were the dominant (87.9%) among OCPs while tri- and tetra- (65.5%) homologue groups among PCBs. Hexa-PCBs, however also showed higher contribution (20.4%) in the region. Source diagnostic ratios of DDE + DDD/DDT (0.1–1.53) indicated both fresh and old input while α-HCH/γ-HCH (0.19–2.49) showed presence of lindane in the region. Higher concentration of OCs were observed in Zone C at altitudinal range of 737–975 masl that are close to the human influences and potential sources of POPs. The results of linear regression analysis revealed potential input of BC in soil distribution of OC concentrations in the region. Black carbon's potential role in OCs distribution in soils of Lesser Himalaya

Sedimentary black carbon and organochlorines in Lesser Himalayan Region of Pakistan:Relationship along the altitude

Black carbon (BC) and total organic carbon (TOC) along with their relationship with organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were assessed in Lesser Himalayan Region (LHR) in different altitudinal zones based on anthropogenic influence/source proximity under the scope of this study. Results revealed the concentrations of BC, TOC, OCPs and PCBs varied between 0.3 and 43.5 mg g− 1, 1.7–65.4 mg g− 1, 0.59–3.64 ng g− 1 and 0.01–1.31 ng g− 1, respectively. Spatial distribution trends have shown higher levels of OCPs and PCBs contamination near populated and urban areas along the altitude. It is implicated that upslope, short and long-range transport and local emission sources contribute to the contamination of different altitudinal zones of LHR. The relationship of BC and TOC with OCPs and PCBs was evaluated using principal component analysis (PCA) and Pearson correlation analysis that indicated higher sorptive influence of BC over TOC in distribution status of organochlorines in LHR. Further research is required to find relationship of BC and TOC in surface riverine sediments, particularly in aquatic systems along the altitude in mountain regions of the world

Characteristics and outcomes of COVID-19 patients admitted to hospital with and without respiratory symptoms

Background: COVID-19 is primarily known as a respiratory illness; however, many patients present to hospital without respiratory symptoms. The association between non-respiratory presentations of COVID-19 and outcomes remains unclear. We investigated risk factors and clinical outcomes in patients with no respiratory symptoms (NRS) and respiratory symptoms (RS) at hospital admission. Methods: This study describes clinical features, physiological parameters, and outcomes of hospitalised COVID-19 patients, stratified by the presence or absence of respiratory symptoms at hospital admission. RS patients had one or more of: cough, shortness of breath, sore throat, runny nose or wheezing; while NRS patients did not. Results: Of 178,640 patients in the study, 86.4 % presented with RS, while 13.6 % had NRS. NRS patients were older (median age: NRS: 74 vs RS: 65) and less likely to be admitted to the ICU (NRS: 36.7 % vs RS: 37.5 %). NRS patients had a higher crude in-hospital case-fatality ratio (NRS 41.1 % vs. RS 32.0 %), but a lower risk of death after adjusting for confounders (HR 0.88 [0.83-0.93]). Conclusion: Approximately one in seven COVID-19 patients presented at hospital admission without respiratory symptoms. These patients were older, had lower ICU admission rates, and had a lower risk of in-hospital mortality after adjusting for confounders