Metal contaminations in sediment and associated ecological risk assessment of river Mahanadi, India

Mahanadi is one of the major rivers of peninsular India. Like other Indian rivers, it is contaminated with sewages, industrial discharges, and agricultural runoff. Thus, necessity was felt to monitor its pollution status. Present work was part of that program and aimed to assess the sediment contamination due to the trace metals Cd, Cr, Cu, Mn, Pb, and Zn during 2012-2015. Sediment pollution status and ecological risks were evaluated calculating contamination factor (CF), geo-accumulation (I_geo), pollution load index (PLI), potential ecological risk (EⁱR), etc. The recorded metal concentrations were Cd BDL of flame mode of AAS; Cr BDL - 73.9; Cu BDL - 44.4; Mn 37.2 - 1887.0; Pb BDL - 29.5; and Zn BDL - 92.5 mg kg^-1. As per US EPA guidelines, Cr concentrations at many locations were in the moderately polluted range. I_geo, CF, mC_d, PLI, and EⁱR indicated low pollution levels and low ecological risks due to the trace metals assessed. The sediment quality guidelines (SQGs) indicated that Cr and Cu concentrations exceeded (16% sample) the threshold effect concentrations and may occasionally exhibit adverse biological effects. The association of sediment organic matter, conductivity and content of Cu, and their grouping in component 1 of PCA revealed that the anthropogenic input was dominant and so also the component 2 where Cr exhibited moderately good correlation with organic matter. Cluster analysis of the sampling sites based on pollution status yielded 3 groups: relatively uncontaminated (S3, S4), low to moderately contaminated (S2), and moderately contaminated (S1, S5, S6) stretches.

Status of pesticide residues in water, sediment, and fishes of Chilika Lake, India

Chilika Lake is the largest coastal lagoon in Asia and the second largest in the world covering an area of 1100 km² and spread over three districts of Odisha state of India. It is the first Indian wetland designated as a wetland of international importance under the Ramsar Convention in 1981. The lake ecosystem sustains large and diversified resources of plants and animals including fisheries. Pollution of the ecosystem caused by residues of pesticides originating from different sources was assessed through multiple sampling from 2012 to 2016 from three potential sites of contamination, viz., Palur Bridge, Daya River Estuary, and Makara River. Incidence of organochlorinated (OC) pesticide residues was noticed in about 25% water samples. HCH (α, γ&δ), DDD (op^|), DDE (op^|&pp.^|) and heptachlor were the OCs detected in concentration varying from 0.025 to 23.4 μg/l. None of the eight targeted synthetic pyrethroid (SP) pesticides was found in water, but among the organophosphates (OP), chlorpyrifos (0.019-2.73 μg/l), and dichlorvos (0.647 μg/l) were recorded. In sediment samples, residues of OC or OP pesticides were not present, but one SP pesticide was recorded. Fish samples were contaminated to the extent of 55%, mostly with residues of OCs and OPs and less with SPs. However, their concentrations were below the permissible limit, so there was no direct threat of health hazards to humans.

Emission of greenhouse gases and soil carbon sequestration in a riparian marsh wetland in central Ohio

Wetlands are a C sink, but they also account for a large natural source of greenhouse gases (GHG), particularly methane (CH₄). Soils of wetlands play an important role in alleviating the global climate change regardless of the emission of CH₄. However, there are uncertainties about the amount of C stored and emitted from wetlands because of the site specific factors. Therefore, the present study was conducted in a temperate riverine flow-through wetland, part of which was covered with emerging macrophyte Typhus latifolia in central Ohio, USA, with the objective to assess emissions of GHGs (CH_4, CO₂, N₂O) and measure C and nitrogen (N) stocks in wetland soil in comparison to a reference upland site. The data revealed that CH₄ emission from the open and vegetated wetland ranged from 1.03-0.51 Mg C/ha/y and that of CO₂ varied from 1.26-1.51 Mg C/ha/y. In comparison, CH₄ emission from reference upland site was negligible (0.01 Mg C/ha/y), but CO₂ emission was much higher (3.24 Mg C/ha/y). The stock of C in wetland soil was 85 to 125 Mg C/ha up to 0.3 m depth. The average rate of emission was 2.15 Mg C/ha/y, but the rate of sequestration was calculated as 5.55 Mg C/ha/y. Thus, the wetland was actually a C sink. Emission of N₂O was slightly higher in vegetated wetland (0.153 mg N₂O-N/m²/h) than the open wetland and the reference site (0.129 mg N₂O-N/m²/h). Effect of temperature on emission of GHGs from the systems was also studied.

Poor efficacy of herbicides in biochar-amended soils as affected by their chemistry and mode of action

We evaluated wheat straw biochar produced at 450°C for its ability to influence bioavailability and persistence of two commonly used herbicides (atrazine and trifluralin) with different modes of action (photosynthesis versus root tip mitosis inhibitors) in two contrasting soils. The biochar was added to soils at 0%, 0.5% and 1.0% (w/w) and the herbicides were applied to those soil-biochar mixes at nil, half, full, two times, and four times, the recommended dosage (H(4)). Annual ryegrass (Lolium rigidum) was grown in biochar amended soils for 1 month. Biochar had a positive impact on ryegrass survival rate and above-ground biomass at most of the application rates, and particularly at H(4). Within any given biochar treatment, increasing herbicide application decreased the survival rate and fresh weight of above-ground biomass. Biomass production across the biochar treatment gradient significantly differed (p<0.01) and was more pronounced in the case of atrazine than trifluralin. For example, the dose-response analysis showed that in the presence of 1% biochar in soil, the value of GR(50) (i.e. the dose required to reduce weed biomass by 50%) for atrazine increased by 3.5 times, whereas it increased only by a factor of 1.6 in the case of trifluralin. The combination of the chemical properties and the mode of action governed the extent of biochar-induced reduction in bioavailability of herbicides. The greater biomass of ryegrass in the soil containing the highest biochar (despite having the highest herbicide residues) demonstrates decreased bioavailability of the chemicals caused by the wheat straw biochar. This work clearly demonstrates decreased efficacy of herbicides in biochar amended soils. The role played by herbicide chemistry and mode of action will have major implications in choosing the appropriate application rates for biochar amended soils.

Organochlorine pesticide residues in bovine milk

Monitoring of bovine milk of different places in Bundelkhand region of India was carried out to evaluate the status of organochlorine pesticide (OCP) residues. Out of a total of 325 samples 206 (63.38%) were contaminated with residues of different OCPs. The average concentration of total HCH was 0.162 mg/kg. Among the different HCH isomers the frequency of occurrence of alpha-isomer was maximum followed by delta-, gamma- and beta. Endosulfan (alpha, beta, sulfate) was detected in 89 samples with mean concentration of 0.0492 mg/kg while total DDT comprising of DDT, DDE and DDD was present in 114 samples having mean concentration of 0.1724 mg/kg. Dicofol was positive in 17 samples.

Environmental transformation of triadimefon in water and on plant leaf surface

Phototransformation of triadimefon was studied in aqueous solution and on plant leaf surface under natural and simulated conditions. Photoproducts such as 4-chlorophenol, 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1,2,4-triazole-1-yl)-butan-2-ol and 1-phenoxy-3,3-dimethyl-but-2-one were identified on leaf as well as in aqueous solution. A new photoproduct product 1-(4-chlorophenoxymethyl)-1,2,4-triazole was identified only on the leaf surface. The rate of degradation was more in tap water as compared to rain and distilled water.

Maximal aerobic capacity of Bengali girl athletes of different sports activities

The maximal aerobic capacity (VO2max) and related cardiorespiratory parameters were determined on 67 Bengalee (Indian) girl athletes having nine different sports activities. VO2max was determined with a bicycle ergometer. The highest value for VO2maxl.min-1 was obtained by javelin throwers (1.95), being followed by pentathletes (1.92) and long-distance runners (1.90), whereas the lowest value was achieved by handballers (1.45). When VO2max was expressed in ml.kg-1.min-1, the long-distance runners registered the highest mean value (43.0), which was significantly higher than that of basketballers (34.9), handball players (36.2), badminton players (34.4), and swimmers (36.0). For this measurement, the sprinters (40.0), pentathletes (40.3), javelin throwers (40.0), and jumpers (39.4) did not differ significantly with each other, but each of the groups was significantly superior to basketballers, handballers, badminton players, and swimmers. No significant difference was also found amongst the latter groups. VO2maxl.min-1 was found to be significantly correlated with all the physical characteristics. It was predicted on the basis of age, height, weight, and body surface area using stepwise regression method.

Spirometric standards for non-smokers and smokers of India (eastern region)

Three hundred thirty-four healthy male non-smokers and 300 healthy male smokers of the age range 20-60 years were investigated for their spirometric lung functions by the method and technique recommended by American Thoracic Society. It was found that FVC, FEV1, FEV1%, FEF 200-1,200, FEF 25-75%, FEF 75-85%, MVV, and PEFR were significantly lower in smokers. When the subjects were blocked into several half decades these differences persisted. These functions deteriorated with age both in smokers and non-smokers, but in the former group the functions were reduced to a greater extent. Significant negative correlation was obtained between lung functions and smoking histories. Separate multiple regression equations were developed separately for non-smokers and smokers. The sensitivity of the tests was determined. The FEF 25-75% and FEV1 were found to be most sensitive in detecting early airway obstruction. When comparison of lung function was made among American, European, Jordanian, Negro, and Pakistani subjects, it was found that the former three groups are superior to the remaining. Negroes and Pakistanis are comparable to Indians in respect to their lung function. These differences in these functions between the nations of developed countries and the underdeveloped or developing countries might be attributable to the differences in their life-style, physical activity status, nutritional status, environmental condition, and race and ethnicity. The spirometric functions of Indians in the Eastern region of India are comparable to North-West Indians and superior to Southern Indians.

Maximum oxygen uptake capacity of smokers of different age groups

Eighty-four healthy asymptomatic sedentary smokers and 92 healthy sedentary non-smokers of the age range 20-59 years were investigated for their maximum oxygen uptake capacity (VO2max) and related cardiorespiratory parameters at the level of maximal exercise by bicycle ergometry. The subjects were blocked into four age decades of 20-29, 30-39, 40-49, and 50-59 years to show the effect of smoking on VO2max of smokes of different age groups. The physical characteristics of smokers and non-smokers of comparable age groups did not show any significant difference. The smokers of each subsequent age group consumed 5.9 +/- 4.1, 6.3 +/- 5.7, 12.7 +/- 7.1, and 11.5 +/- 9.1 pack years of cigarettes, respectively (pack year = number of packets of cigarettes per day X number of years of smoking). VO2max of smokers (38.9 +/- 4.6 ml.kg-1.min-1) was significantly lower (p less than 0.05) than that of nonsmokers (42.1 +/- 3.2 ml.kg-1.min-1) only in the young age group of 20-29 years. VO2max expressed in per kg of the body weight (VO2max/BW) was found to be significantly (p less than 0.01) and negatively correlated with number of cigarettes smoked per day (-0.36, p less than 0.01), number of years through which smoked (-0.38, p less than 0.01), and pack years (-0.42, p less than 0.01). In other age groups, though non-smokers predominated over smokers in VO2max, the differences were not statistically significant. Also, in these age groups, smoking histories failed to reveal any significant correlation with VO2max. This suggests that smoking impairs VO2max only in the young ages. By increasing age, VO2max was diminished by 13% from 20 to 59 years in non-smokers and 15.5% from 20 to 59 years in smokers. Age also diminished HRmax and VEmax of smokers in the same manner as in the case of non-smokers. The VO2max of Indian sedentary non-smokers was found to be lower than those of Caucasians, Kurds, Yemenites, Europeans, and Africans. Values reported on Asians were found to be comparable with those of the present study.

Primary carcinoma of male urethra

Carcinoma of the male urethra is infrequent. To date approximately 600 cases have been reported. We reviewed 16 cases of carcinoma of the male urethra seen at the University of Tennessee and the Memphis Veterans Administration Hospital. The mean patient age was sixty-three years (range 38 to 84). The most common presentation was a palpable mass followed by symptoms of urinary obstruction. Five urethral carcinomas arose distal to the suspensory ligament of the penis while 11 were of bulbar or bulbomembranous origin. The histology was squamous cell carcinoma in 8 patients (50%), mixed squamous and transitional cell carcinoma in 5 (31%), transitional cell carcinoma in 2 (13%), and adenocarcinoma in 1 (6%). The mean patient survival was fifteen months following diagnosis of a proximal urethral tumor and seventy-seven months for tumors arising distally. Neoplasms of the distal urethra can be surgically managed successfully even if regional lymph nodes are involved. The prognosis for proximal urethra tumors remains poor and is best treated by a combination of surgery and radiotherapy.

Carcinoma of the female urethra: reassessment of modes of therapy

Of 15 women with primary urethral carcinoma 2 had tumors confined to the urethra and were managed successfully by an operation. Of the 9 patients with tumor extending to the surrounding structures 6 (67 per cent) died of complications related to inadequate control of the primary tumor. The last 4 patients had stage D1 disease or greater at initial diagnosis and died of distant metastases. Our current approach for patients with locally advanced disease is combined brachytherapy and operation in an effort to eradicate the primary tumor, since morbidity and mortality result from failure to control the local tumor.