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Oct 2021 DOI 10.14302/issn.2641-7669.ject-21-3970
Dias Toledo Arruda-Neto JoaoCorresponding author
Linear Accelerator Laboratory, Physics Institute, University of Sao Paulo, São Paulo-SP, Brazil
Microcystins (MCs) are toxins profusely synthesized by cyanobacteria, causing livestock poisonings and endangering human health. We design and execute an experiment to investigate the attenuation (degradation) of microcystins by exposing them to gamma radiation and electron beams at doses of 0 (control), 3, 5, 10 and 15 kGy. The experimental conditions simulate microcystin contamination of aquatic environments; we thus consider (1) microcystins inside whole cells and extracellular dissolved in water, simulated by non-sonicated and sonicated cells, respectively, and (2) two acute microcystin concentrations within water. Toxicity tests of Microcystis aeruginosa detected immobilization (i.e., paralysis) of Ceriodaphniasilvestrii exposed to aqueous crude extracts of irradiated and non-irradiated M. aeruginosa (NPLJ-4 strain) at concentrations of 45 and 90 mg.L-1 (mg dry weight of freeze-dried material), and the results were analyzed using the Trimmed Spearman-Karber statistical program to obtain 48-h EC50, the average effective concentration causing immobility in 50% of organisms after 48 hours. We conclude that electron beams are effective physical agents for toxin attenuation (degradation) and reach 100% effectiveness at 5 kGy and above; their efficiency is two orders of magnitude greater than that of gamma radiation. This new body of information contributes to (1) remediating environmental water sources; (2) designing water/wastewater treatment facilities; (3) combatting chronic microcystin environmental contamination; and (4) inspiring further studies to promote the use of biomonitors (e.g., Cladocerans) to detect and evaluate microalgae contamination.
Dec 2018 DOI 10.14302/issn.2691-3208.ijli-18-2476
H Radwan ECorresponding author
Faculty of Science, Damanhour University, Egypt
Bivalves are used as bioindicators of heavy metals pollution because they are known to concentrate these elements, providing a time integrated indication of environmental contamination. Trace metals can reach high concentrations in sediments and also in aquatic organisms by bioaccumulation through the food chain. Six heavy metals (Hg, Zn, Pb, Fe, Mg and Cu) were collected and investigated from Abu Hummus, El Behara. The concentration of Hg was high in winter as 2.3µg/g in sediment. The Zn concentration was high in summer in sediment as 8.1µg/g. The Pb concentration was high in winter in water as 3.3µg/l. The concentration of Fe in sediment was high in summer as 492 µg/g. The concentration of Mg was high in sediment as 408µg/g. The concentration of Cu was high in summer in sediment as 301µg/g. The mean concentrations of Fe in the present study are within the permissible limits of law 48/1982 (<1 mg/l) and the guideline of (WHO, 1993) which is <1 mg/l. The mean concentration level of copper is within the permissible limits of law 48/1982 (<1.0 mg/l). The mean levels of the heavy metals (Hg, Zn, Pb, Fe, Mg and Cu) detected in the present study in the water stream are less than the permissible limits recommended by (USEPA, 2005). In the present study there is a significance between all seasons in the protein content in the soft tissue of Spathopsisrubensas the mean concentration level in Spring was reported as 102.83mg/g which is higher then that of autumn 100.5mg/g, summer 93.33 mg/g and winter 80.50 mg/g. In the present study the mean activity level of GPx in spring was higher than the other seasons such as spring 31.33u/g ˃ summer 28.33 u/g ˃Autumn 26.67 u/g ˃ winter 20.50u/g. The mean activity level of SOD in summer was higher than the other seasons such as summer 38.83 u/g ˃ spring 33.33 U /g ˃Autumn 28.83U/g ˃ winter 22.83U/g. The mean activity level of CAT in spring was higher than the other seasons such as spring 25.67u/g ˃ summer and autumn19.83u/g ˃ winter 15.17u/g. The mean activity level of MDA in winter was 30.50 U/g ˃ summer 22.50U/g ˃ autumn 18.0 U/g ˃ spring 16.83U/g. In the present study it was found that the mean activity level of MDA increased in winter at the same time the mean activity level of CAT, SOD and GPx were decreased in winter. Negative correlation was reported between CAT and Hg in winter as r=-0.88*. A positive correlation coefficient in winter was found between SOD activity level and CAT activity level as r=0.838*.
Jul 2016 DOI 10.14302/issn.2474-3585.jpmc-16-1114
Okwundu Nwankwo InnocentCorresponding author
Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, Usmanu Danfodiyo University Sokoto, Nigeria.
Campylobacter infection has been detected in poultry processors at live bird markets in Sokoto, however the prevalence of Campylobacter species in more diverse group of the population is uncertain. For this purpose, 292 human fecal swabs from patients in four Government Hospitals in Sokoto State were analyzed for Campylobacter species using culture and phenotypic typing method. The prevalence rate of 55% was revealed in the tested samples while 56% and 55% were for males and females respectively. Campylobacter jejuni, C. coli and C. lari had 20%, 40% and 40% in males and 38%, 35% and 27% in females respectively. The prevalence rates of 60%, 52%, 45%, 41% and 80%,were revealed in age range of (less than 1-6, 7-13, 14-20, 21-55 and 56-76) yrs respectively. Furthermore, 70% and 43% prevalence rates were recorded in pregnant and non-pregnant women of reproductive age respectively. There was no statistical significant association (P>0.05) between Campylobacter infection and age range and sex, but the statistical association between infection and pregnancy was significant (P<0.05). The prevalence of Campylobacter species in patients as found in the various hospitals has revealed the level of environmental contamination in different homes in the state and the need to include Campylobacter in screening routine laboratory diagnosis of gastroenteritis in humans for appropriate treatment and management especially in young children, old adult and pregnant women.