TOXICITY OF SEA GRASS EXTRACT (Eucheuma cottonii AND Gracillaria sp) TO LARVA Artemia salina

Seaweed is a source of foreign exchange, namely as a main export product and a source of income for coastal communities. Previous research on species Eucheuma cottonii and Gracillaria sp contain bioactive compounds that can be used in medicine, for example as anti-cancer. The purpose of this study was to determine the LC50 value and safe concentration of Artemia salina larvae. The research was conducted at the Chemical Oceanography Laboratory of the Department of Marine Sciences, Faculty of Fisheries and Marine, Riau University in July 2020. The method used in this research is the experimental method. The results of the research on the toxicity of the n-hexane extract of seaweed E. cottonii and Gracillaria sp had bioactivity compounds against A. salina shrimp larvae, indicated by a small LC50 value (<1000 ppm), namely 62.62 ppm for E. cottonii and 83.55. ppm for Gracillaria sp, so it is included in the toxic category. According to research by experts, if the extract or compound tested is less than 1000 ppm, it is considered that there is biological activity. For a safe concentration for the survival of A. salina, 6.262 ppm for E. cottonii and 8.355 ppm for Gracillaria sp.

Long-term Exposure to Phenanthrene-Induced Gene Expressions and Enzyme Activities of Cyprinus Carpio Below the Safe Concentration

Phenanthrene (PHE) is a typical food chain biomagnified compound which endangers human health and is generally accumulated from marine lives. Previous PHE-stressed Carp acute toxicity test showed that the safe concentration of PHE to carp was 1.12 mg/L. In this study, the carp was long-term exposed to PHE below safe concentration up to 25 days. The gene expression levels and cytochrome P450 (CYP1A/EROD (7-Ethoxylesorufin O-deethylase)) and glutathione S-transferase (GST) activities were determined in the carp liver and brain tissues. The results showed that both the CYP1A mRNA expression and EROD activity in the liver were continuously stimulated after induction with the increase in exposure time and exposure concentration. However, with the increase of PHE concentration, GST mRNA expression in the liver was firstly induced and then inhibited and the induction was significant in the treatment with 0.1 mg/L PHE in the 15th day (almost 2-fold). In the brain, after the 15th day, GST mRNA expression was suppressed, but GST activity was induced. Correlation analysis results showed that the CYP1A mRNA expression was significantly correlated with the activity of EROD in both tissues (liver, r = 0.602, P < 0.01; brain, r = 0.508, P < 0.01), but the correlation between GST mRNA expression and GST activity was poor (liver, r = 0.385, P < 0.01; brain, r = 0.293, P < 0.01). This experiment revealed the self-regulation mechanism of carp exposed to lower than safe concentrations of PHE for a long time, indicating the toxicological risk of PHE in the ecosystem.

The Determination of Safe Concentration of Non-Carcinogenic Toluene in Surabaya Printing

Introduction: Safe concentrations of non-carcinogenic toluene can cause adverse effects on health. Based on the results of a research, toxic effects on toluene exposure can cause cancerous (leuikimia) and non-cancerous (aplastic anemia). The Research objective to determine the safe concentration of non-carcinogenic toluene in Surabaya printing. Methods: The research design used was observational analytic, cross sectional research design with a quantitative approach. The research location was a printing press in Surabaya. The variables in this study were the concentration of toluene levels (ppm) and RQ in workers. Total population was 37 workers, while the study sample was taken using accidental sampling method with a total sample of 30 respondents. The formula for determining the concentration of toluene non carcinogen intake is (CxRxtExfExDt): (Wbx30x365). Results: The concentration value of toluene exposure was greater than the standard set by labor regulations No. 5 of 2018 about occupational health and safety of the work environment by 0.2 ppm. A total of 10% of workers falls under normal category, 73% above normal category and 27% below normal category. Conclusion: In this study, we found new findings, viz the concentration of toluene exposure in Surabaya printing area was above normal with a concentration of 0.2 ppm and this is considered not normal.Keywords: non carcinogenic toluene, safe concentration, surabaya printing, toluene

Remediation of zinc contaminated soils from a farm settlement in Nigeria

This work is on remediation of zinc concentration (330.0 mg/kg) in soils from farm settlement at Agbabu community in Ondo State of Nigeria to below maximum allowable 300 mg/kg specified for safe agriculture by standards to ensure that farm products from this farm settlement close to area of mining are safe for human beings. Three indigenous organisms: Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and Proteus mirabilis (P. mirabilis) were engaged for the remediation study. The organisms were isolated and cultured. Optimum weights of the distinct organisms were inoculated in 4g soils each conditioned with optimum values of pH, temperature, stirring frequency and nutrient in thirty-six 50 ml beakers; and experimented for residual zinc ion at times 5, 10, 15, 20, 25, 30 and 35 days in triplicate with Atomic Absorption Spectrophotometer. Each organism maintained its performance position from day 5 to day 35. Bacillus subtilis took the lead, seconded by P. mirabilis while E. coli lagged. Removal to safe concentration first occurred at 10 days for B. subtilis, 15 days for P. mirabilis and 20 days for E. coli with respective 292.09 mg/kg, 294.37 mg/kg, and 290. 71 mg/kg residual concentrations. The respective residual concentrations and efficiencies at 35 days were 247.33 mg/kg and 25.06 %; 253.47 mg/kg and 23.20 %; and 267.11 mg/kg and 19.07 %. Two-ways ANOVA at (P < 0.05) showed that a combination of 2 or 3 of the organisms would result in lower residual concentration; and relevant performances at shorter times. Keywords: Zinc, contaminated soils, farm settlement, bioremediation

Effects of two kinds of fishery drugs on the expressions of GAD and GABA-T mRNA in crucian carp (Carassius auratus gibelio)

The objective of this study was to investigate the effects of difloxacin (DIF) and avermectin (AVM) on glutamate decarboxylase (GAD) and GABA-transaminase (GABA-T) in different tissues of crucian carp (Carassius auratus gibelio). After the treatments of DIF and AVM, the mRNA expressions of GAD and GABA-T in different tissues were detected by quantitative real-time PCR (qPCR). The results showed that the mRNA expressions of GAD65, GAD67, and GABA-T in the telencephalon (Tel), mesencephalon (Mes), cerebella (Cer), and medulla oblongata (Med) were downregulated significantly with the safe dose (SD, 20 mg/kg) of DIF (P < 0.05 or P < 0.01). While the expressions of GAD65 and GAD67 in the kidney at 12 h had strikingly upregulated to 13.81 ± 1.06** and 150.67 ± 12.85** times. Treated with the lethal dose of 50% (LD50, 2840 mg/kg b. W.) of DIF, the mRNA expressions of GAD65, GAD67, and GABA-T in all tissues were increased significantly (P < 0.01). The results of AVM group showed that the mRNA expressions of GAD65, GAD67, and GABA-T both in the central and peripheral tissues were all remarkably downregulated at the safe concentration (SC, 0.0039 mg/L) and the lethal concentration of 50% (LC50, 0.039 mg/L), except for the mRNA inhibitions of GAD65, GAD67, and GABA-T in the muscle at 2 h which sharply downregulated to 0.20 ± 0.02ΔΔ × 10−2, 0.57 ± 0.06ΔΔ × 10−1 and 0.44 ± 0.02ΔΔ × 10−1, respectively (P < 0.01).

The Toxicity of Ethanolic Extract of Alchornea cordifolia Leaf on Clarias gariepinus Fingerlings

Acute toxicity effects of ethanol extract of Alchornea cordifolia leaf on Clarias gariepinus fingerlings was investigated over a 96hr exposure period as a potential organic piscicide. A static toxicity bioassay was performed after preliminary trial tests (range-finding test) were conducted. Five hundred (500) post-fingerlings of Clarias gariepinus were distributed randomly in duplicate concentrations. The test fishes were treated with concentrations of 1.31, 1.96, 2.97, 4.45 and 6.67 mg/1 of Alchornea cordifolia. Exposure to the plant toxicant caused visible behavioural changes which include erratic swimming, air gulping, discolouration, loss of body equilibrium, the settlement at the bottom and death. Mortality was recorded in some of the exposed fish while the LC50 lethal concentration of 2.138 mg/1 was established and safe concentration was established as 0.2138 mg/l. There were significant changes (p˃0.0.5) in the water quality parameters except for electrical conductivity, the unstable behaviour of the fish must have been as a result of irritation from the toxicant. Therefore, the use of A. cordifolia in fish harvesting should be regulated and not allowed to gain access unnecessarily into the aquatic ecosystem and regulatory bodies should maintain the safe concentration of 0.2138 mg/l.