Longitudinal Chemical Gradients and the Functional Responses of Nutrients, Organic Matter, and Other Parameters to the Land Use Pattern and Monsoon Intensity

River water quality degradation is one of the hottest environmental issues worldwide. Therefore, monitoring water quality longitudinally and temporally is crucial for effective water management and contamination control. The main aim of this study was to assess the longitudinal variations in water quality in the mainstream of the Han River, Korea, from 2015 to 2019. The trophic state classification (TSC), microbial pollution indicator (MPI), and river pollution index (RPI) were calculated to characterize river water quality and revealed more serious pollution toward the downstream zone (Dz) due to agricultural and urban-dominated areas. The biodegradability index (BI) indicated that non-biodegradable organic pollutants are increasing in the water body from the urban and animal wastewater treatment plants. Nutrients, organic matter contents, total suspended solids, ionic factors, and algal chlorophyll were higher in the Dz than in any other zones and were markedly influenced by the summer monsoon. Empirical analysis showed that nutrients and organic matter had positive linear functional relations with agricultural and urban coverage and negative linear relations with forest coverage. The pollutant-transport function suggested that suspended solids act as TP and TN carriers. Regression analysis indicated that TP (R2 = 0.47) has more positive functional relations with algal growth than TN (R2 = 0.22). Our findings suggest that a combination of empirical models and pollution indices might be utilized to assess river water quality and that the resulting information could aid policymakers in managing the Han River.

Low Level Carbon Dioxide Indoors—A Pollution Indicator or a Pollutant? A Health-Based Perspective

With modern populations in developed countries spending approximately 90% of their time indoors, and with carbon dioxide (CO2) concentrations inside being able to accumulate to much greater concentrations than outdoors, it is important to identify the health effects associated with the exposure to low-level CO2 concentrations (<5000 ppm) typically seen in indoor environments in buildings (non-industrial environments). Although other reviews have summarised the effects of CO2 exposure on health, none have considered the individual study designs of investigations and factored that into the level of confidence with which CO2 and health effects can be associated, nor commented on how the reported health effects of exposure correspond to existing guideline concentrations. This investigation aimed to (a) evaluate the reported health effects and physiological responses associated with exposure to less than 5000 parts per million (ppm) of CO2 and (b) to assess the CO2 guideline and limit concentrations in the context of (a). Of the 51 human investigations assessed, many did not account for confounding factors, the prior health of participants or cross-over effects. Although there is some evidence linking CO2 exposures with health outcomes, such as reductions in cognitive performance or sick building syndrome (SBS) symptoms, much of the evidence is conflicting. Therefore, given the shortcomings in study designs and conflicting results, it is difficult to say with confidence whether low-level CO2 exposures indoors can be linked to health outcomes. To improve the epidemiological value of future investigations linking CO2 with health, studies should aim to control or measure confounding variables, collect comprehensive accounts of participants’ prior health and avoid cross-over effects. Although it is difficult to link CO2 itself with health effects at exposures less than 5000 ppm, the existing guideline concentrations (usually reported for 8 h, for schools and offices), which suggest that CO2 levels <1000 ppm represent good indoor air quality and <1500 ppm are acceptable for the general population, appear consistent with the current research.

Assessment of Physicochemical Parameters and Phytoplankton of Eme River, Umuahia, Southeast Nigeria

Aquatic ecosystems respond differently to diverse anthropogenic activities in their watersheds. Phytoplankton is sensitive to their environment and is used to monitor anthropogenic impacts. A study was carried out in a South-eastern Nigerian River between December 2017 and November 2018 in 6 stations; to assess the phytoplankton community, water quality, and anthropogenic impacts. Sand mining was a major activity in the river among others. The phytoplankton was sampled with the filtration method while water was collected and analyzed using standard methods. A total of 36 phytoplankton species were recorded with Chlorophyceae being the most abundant group. The most abundant species - Melosira granulata is a pollution indicator. The water quality and phytoplankton structure showed that the water was tending towards eutrophication. This is attributed to the observed anthropogenic activities and cumulative impacts of all the activities in the watershed. The impact of sand mining activities was observed more in the downstream stations (4 – 6) while perturbation from swimming children and related activities was observed in station 1. The community structure reflected the impacts of the activities while CCA showed the major water quality parameters that influenced the phytoplankton community structure.

Relationship between macrobenthos and abiotic characteristics of river Alaknanda in a stretch from Chamoli to Devprayag in Garhwal Himalayan region of Uttarakhand, India

Macrobenthos is the best water quality indicator for ecosystem health assessment. The present study aimed to examine the interrelationship between macrobenthos and different water quality parameters of the river Alaknanda at Garhwal Himalaya. Four demarcated sampling zones viz. zone-A (Chamoli to Nandprayag), zone-B (Karanprayag to Rudraprayag), zone-C (Rudraprayag to Srinagar) and zone-D (Srinagar to Devprayag) were taken from its approximately 170 km long stretch during 2016-2018. River water characteristics were analyzed for the important parameters viz. substratum, water temperature (WT), water velocity, pH, electrical conductivity (EC), total dissolved solids (TDS), calcium (Ca), and magnesium (Mg) using standard methods. The results indicated that the river water velocity was the highest 1.02 m/s at zone-C, TDS of 114.19 mgl-1 was maximum at zone-A ; and Ca and Mg were recorded highest 23.17 mgl-1 and 5.44 mgl-1 at zone-A and zone-B, respectively. All abiotic parameters (pH, EC, TDS, DO, Ca and Mg) were recorded to be below BIS/WHO limits. A total of 27 macrobenthos taxa belonging to the five orders such as Coleoptera (6 ind./m2), Diptera (5 ind./m2), Ephemeroptera (8 ind./m2), Hemiptera (4 ind./m2), and Odonata (4 ind./m2) were recorded. Macrobenthos represented an important relationship between the water current and water temperature. The lowest number was reported at zone-C due to the river's high water velocity (1.02 m/s). The changes like biota loss, presence of some pollution indicator species (Cloeon sp., Bateis sp., Emphemera sp.) at zone-C, in sediment structure of habitat were due to the anthropogenic activities on the riverbank of different zones. The study will help in the conservation of macrobenthos diversity of the river Alaknanda.

Monitoring the Influence of Anthropogenic Pollution on the Quality of Irrigation Water for Market Gardening in Yamoussoukro, Côte d’Ivoire

Background: The microbiological quality of three vegetable crops (cabbages, carrots, lettuces) and their irrigation water from the lake system of the city of Yamoussoukro were studied. The pollution indicator used is Escherichia coli (E. coli), of the thermotolerant coliform family. Methods: During the period 2017-2019, in four dry and four wet seasons, a total of 744 water samples and 13392 vegetable samples were collected in five (5) lakes belonging to the lake system. The lakes were selected because of their position in the system. The E. coli loads were evaluated after isolation on a specific COMPASS ECC Agar and confirmed with Polymerase chain reaction (PCR) and the physicochemical parameters of the lakes, evaluated according to their respective ISO standards. Result: In irrigation waters, bacterial loads and physico-chemical parameters generally have evolved from the upstream lakes to those downstream of the lake system (from lake A to lake E). Values were higher during the rainy seasons. E. coli loads on vegetables were strongly correlated with those of irrigation water, especially in dry seasons. Spearman’s correlations revealed significant correlations between turbidity, DOC and bacterial loads. The risk of bacterial transmission between lake waters and surrounding vegetables is proven.

Variation of Aulacoseira Granulata As An Eco-Pollution Indicator In Sub-Tropical Large River Ganga In India: A Multivariate Analytical Approach

Aulacoseira granulata (Ehrenberg) Simonsen 1979 is one of the major ecological indicators of the water quality of lotic as well as lentic aquatic ecosystems. To assess major environmental factors contributor to A.granulata bloom in the riverine system, a study was carried out from 2018 to 2019 comprising four different seasons at 11 sampling sites of river Ganga in the middle and lower stretch of river Ganga comprising freshwater and estuarine zones. For the analysis, different univariate, as well as multivariate analytical tools such as Principal Component Analysis (PCA) and Water pollution Index (WPI), were used. In the finding, it was observed that the average abundance of Aulacoseira granulata was found maximum during the winter season. Among all the studied sites, the maximum average abundance was at Balagarh (71576 cell l-1) and minimum at Diamond Harbour (68 cell l-1). The environmental factors such as dissolved oxygen, depth, and altitude showed a positive and water temperature negatively influencing the growth rate of A. granulate. WPI showed a significantly negative correlation with cell length. Finally, the study concludes that the blooming of Aulacoseira granulata is highly influenced by varied environmental conditions along the river Ganga suggesting possible eutrophication. Therefore, a certain minimum flow and depth especially during the lean season have to be maintained for the sustenance of planktonic biota in the river Ganga.

MORPHOLOGICAL CHANGES IN PLANTS AS A PARAMETER BIOINDICATION ASSESSMENT

Morphological changes in plants are widely used as an indicator. This is an important indicator parameter. The reason for its widespread use is its low cost, availability and simplicity of research, no need for highly qualified personnel and the presence of a special laboratory. Numerous studies are devoted to the standardization of the test material and the conditions for its use. The national monitoring system of all developed countries includes a large arsenal of morphological indicators, which made it possible to create maps of anthropogenic impacts. The aim of the research is to study the possibility of using morphological changes in plants as a parameter of bioindication assessment. Material and methods: theoretical - analysis of literature on the problem of environmental monitoring, laboratory. Assessment of the degree of plant change is associated with internal factors and different sensitivity of plant organisms. For the purpose of active monitoring, a large group of plants is recommended. For passive monitoring and determination of the consequences of environmental pollution, indicator signs of plants growing freely in the study area are used. Bioindication methods are useful for assessing the state of the environment. The study of the reaction of plants to the level of pollution makes it possible to assess its consequences. The study of urban communities makes it possible to develop ways to stabilize them, for example, by changing loads. Bioindication is an important addition to instrumental methods.

Water Quality of Streams and Springs around a Municipal Landfill Surrounded by Intense Agricultural Activities in a Tropical Environment

In Cameroon waste disposal by open dumping and landfilling are the most practised options. The siting, operation and after-care of landfills remain a challenging task. In this study we assessed water quality of stream, spring and leachate samples around/from the Mussaka landfill through physicochemical, heavy metal, microbial, phytoplankton, and benthic algae analyses. HCO3-, NH4-, NO3- concentrations are all above permissible limits EPA and WHO standards for freshwater systems. Concentrations of Ca2+ and Mg2+ in stream samples were far below standards but far greater (>480 mg/L) in spring and leachate samples. Nickel, lead and cadmium concentrations were above required standards. Contamination factors of all stream samples (CF<3) imply low to moderate contamination but pollution load index for spring sample (PLI>1) imply the spring is polluted. Generally, the obtained concentrations of most of these parameters were far higher for leachate than water samples. Total coliform counts ranged from 3.5 MPN/100mL to 1.1x103 MPN/100 mL. Five E. coli species were detected in all samples in counts ranging from 3.0x102 to 1.0x103CFU/mL. Thirty phytoplankton species belonging to 5 divisions were identified with Bacillariophyta (19 species) having the highest abundance and Euglenophyta (1 species) with least. Ten genera were identified as pollution indicator species. Results of this study justify the assertion that if upgrading options are not sought for the Mussaka landfill, it will become a major source of pollution of aquatic and soil ecosystems within the landfill area and downstream.