Determination of pesticide residues in the serum of flower farm workers: A growing occupational hazards in low income countries.

Ethiopia is one the major exporter of cut flowers in East Africa. However, the sector is blamed for the intensive use of pesticides which leads to exposure of workers. This study aims to investigate the level of pesticides in blood serum of flower farm workers as a predictor to occupational exposure. A cross-sectional laboratory based study was conducted in central Ethiopia among 194 flower farm workers. Blood sample were collected from 100 study participants (50 from farm workers and 50 civil servants as control). Blood-serum separation, extraction, and clean-up was performed following standard analytical methods. Ten organochlorine pesticides (OCPs) (o,p'-DDT, p,p'-DDD, p,p'-DDE, p,p'-DDT, heptachlor, heptachlor epoxide, endosulfan, dieldrin, methoxychlor, dibutychloridate), and three pyrethroids (cypermethrin, permethrin and deltamethrin) were detected in the serum of the study participants. From the detected pesticides p,p'-DDT and p,p'-DDE were observed at high mean concentration (81.5 ± 83.5, and 12.5 ± 6.7 ng/mL),(38.0 ± 31.8 and 6.84 ± 7.4 ng/mL) in the flower farm and controls, respectively. From the Mann-Whitney U-test, there is a significant difference for total DDT (P < 0.02), p,p'-DDE (P < 0.001), cypermethrin (P < 0.001), heptachlor (P < 0.04), heptachlor-epoxide (P < 0.001) and dibutyl chlorendate (P < 0.01) among the flower farm workers and controls. Multinomial regression revealed, being flower farm worker is a significant predictor of moderate to high residues of p,p'-DDE, total DDT, heptachlor-epoxide and dibutyl chlorendate. The pesticides under study were detected more frequently in the flower farm workers than controls which is an indicative for occupational exposure to pesticides and strict regulation is important for the safety of workers.

Removal of Cr(VI) from Aqueous Solutions Using Biowastes: Tella Residue and Pea (Pisum sativum) Seed Shell.

The wide use of chromium (Cr) in different industries led to the release of a considerable amount of Cr(VI) into water bodies. Exposure to Cr(VI) can cause diseases in humans and animals. Therefore, low-cost technology for Cr(VI) removal is required. In this study, the biowastes, "Tella" residue (TR) and Pea (Pisum sativum) seed shell (PSS), were evaluated for their Cr(VI) removal efficiency from aqueous solutions. The physicochemical properties of adsorbents were studied, and the adsorbents were further characterized using FTIR and XRD. Batch adsorption experiments have shown that the Cr(VI) uptake was pH-dependent and found to be effective in a wide range of pH values (pH 1 to 10) for PSS. The kinetics of Cr(VI) removal by the adsorbents was well expressed by the pseudo-second-order model. The experimental equilibrium adsorption data fitted well with Freundlich isotherm indicating multilayers adsorption. The estimated Cr(VI) adsorption capacities of TR and PSS were 15.6 mg/g and 8.5 mg/g, respectively. On top of this, the possibility of reusing adsorbents indicates the potential applicability of TR and PSS for the treatment of Cr(VI) contaminated water. Further study on the evaluation of the efficiency of the adsorbents using real chromium-contaminated wastewater is recommended.

Spectroscopic Determination of Fluoride Using Eriochrome Black T (EBT) as a Spectrophotometric Reagent from Groundwater.

Fluoride health problem is a great concern worldwide, most often as a result of groundwater intake. Thus, determination of fluoride is vital to take appropriate measures upon fluoride contamination of water. Potentiometric method of analysis is reliable for the determination of fluoride in various samples. In addition, spectroscopic methods are found important to quantify fluoride levels from water; however, several factors hinder its easier determination. Among the bottlenecks, the use of toxic chemicals and tedious steps in preparing chemicals (e.g., SPADNS method) are to mention a few. In this study, a spectrophotometric method was developed for the determination of fluoride from groundwater using Eriochrome Black T (EBT) as a spectroscopic reagent. Experimental parameters that influence the determination of fluoride including ligand type, kinetics, pH, and ligand-to-metal ratio were assayed. Evaluation of fluoride levels showed that Beer-Lambert's law is obeyed in the range of 0.3-5.0 mg/L at 544 nm. The calibration curve, resulting in good linearity (R 2 = 0.9997), was considered during quantitative analysis of the samples and in the spiking analysis. The limits of detection (LOD) and quantification (LOQ) of the method were found to be 0.19 and 0.64 mg/L, respectively. The precision studied in terms of intraday and interday at three concentration levels showed less than 5.4% RSD. Applicability of the method was investigated by analyzing groundwater samples spiked with fluoride standards, and satisfactory recoveries in the range of 98.18-111.4 were demonstrated. The developed spectrophotometric method has been successfully applied for fluoride determinations in groundwater samples. Thus, it could be used as an attractive alternative for the determination of fluoride from groundwater.

Exploring the association between childhood diarrhea and meteorological factors in Southwestern Ethiopia.

Childhood diarrhea has been one of the major public health concerns in countries that have limited resources like Ethiopia. Understanding the association between childhood diarrhea and meteorological factors would contribute to safeguard children from adverse health effects through early warning mechanisms. Thus, this study aimed at exploring the association between childhood diarrhea and meteorological factors to enable reducing health risks. A retrospective study design was used to explore the association between meteorological factors and childhood diarrhea in southwestern Ethiopia from 2010 to 2017. Mann Kendall trend test and Spearman's correlation were computed to test the association of childhood diarrhea and meteorological factors. The space-time permutation model was used to identify the risky periods, seasons with most likely clusters, and high childhood diarrhea. Similarly, a negative binomial regression model was fitted to determine the predictability of meteorological factors for childhood diarrhea. The highest childhood diarrhea morbidity was 92.60 per 1000 per under five children. The risk of childhood diarrhea increased by 16.66% (RR: 1.1666; 95% CI: 1.164-1.168) per increase in 1 °C temperature. Furthermore, rainfall was found to be a significant risk factor of childhood diarrhea, with 0.16% (RR: 1.00167; 95% CI: 1.001306-1.001928) per 1 mm increase in rainfall. The temperature was positively correlated with the occurrence of childhood diarrhea. But the association with rainfall showed spatial variability. The space-time permutation model revealed that dry season was found to be a high-risk period with excess childhood diarrhea. The results showed that the observed association between meteorological factors and childhood diarrhea could be used as evidence for early warning systems for the prevention of childhood diarrhea.