Impact of abattoirs and local textile (Adire and Kampala) effluents on Yemoja River in Abeokuta, Nigeria.

Discharge of untreated wastewater into water bodies pollutes the receiving waters. This study assessed the impact of abattoir and Kampala designers' effluent discharge on the water quality of the Yemoja River in Abeokuta, Nigeria. Twenty-seven water samples collected at three points, covering 180 m length, for 6 months were assessed for physicochemical parameters and metals and compared with the World Health Organization (WHO) and Standard Organization of Nigeria (SON) permissible standards. Most discharge point levels were found to be higher than their corresponding upstream and downstream values. Temperature, turbidity, magnesium, alkalinity, DO, TSS, phosphate, lead, BOD and potassium were found to be higher than normal levels for river water as prescribed by the WHO and SON while parameters like TDS, TS, calcium, chloride, nitrate, sulphate, iron and COD were lower than the standards. The total coliform values were higher than both national and international permissible limits, indicating contamination by human sewage or animal droppings. The water quality index indicated polluted water that is unfit for consumption. Findings from this research indicate that butchering and tie-and-dye activities have impacted river Yemoja water quality. Therefore, wastewater from the abattoir and textile industries be treated before discharge into water bodies.

Nutrient enhancement potentials of moringa (Moringa oleifera), neem (Azadirachta indica), and pawpaw (Carica papaya) fortified composts in contaminated soils.

This study assessed the nutrient enhancement potentials of moringa (Moringa oleifera), neem (Azadirachta indica), and pawpaw (Carica papaya) fortified composts in contaminated soils. The composts were formulated from poultry manure; leaves of moringa, neem, and pawpaw; and sawdust for a period of 8 weeks. Contaminated soil samples were collected from a dumpsite in Abeokuta, Ogun State. The contaminated soils were treated with the stabilized composts for a period of 4 weeks. Castor oil plants were introduced to assess the nutrient quality of the composts. Soil and compost parameters (pH, electrical conductivity (EC), organic carbon (OC), total nitrogen (TN), C/N ratio, P, K, Na, Mg, and Ca) were determined using the standard procedures. Data collected were evaluated for simple descriptive and inferential statistics. Results showed non-significance (p > 0.05) of C/N ratios that ranged between 12.75 ± 2.43 and 12.96 ± 1.49. The pH values of moringa- and neem-fortified composts were slightly acidic, while the pawpaw-formulated compost was slightly alkaline. The levels of TN and OC were three times higher in moringa- and pawpaw-fortified composts than in the neem compost. Introduction of the composts to the contaminated soils decreased the soil pH but increased the nutrient quality parameters such as TN (33-50%), OC (56-77%), P (7-20%), Na (89-91%), K (12-25%), and Mg (10-13%). The three compost types increased the physiological properties of the castor oil plants. The study indicated the promising potentials of the three composts for nutrient enhancement of soil.

Ecological assessment of Black Fly (Simuliumdamnosum, Sensulato) breeding sites in two tributaries of Ogun river, Ogun state, Nigeria.

Onchocerciasis is a disease transmitted by blackfly vector of the genus Simuliumdamnosum complex having public and socio-economic consequences. The abundance of blackfly is directly linked to fluvial ecosystems in both tropical and non-tropical countries of the world. This study assessed the ecology of blackfly breeding sites in two tributaries of River Ogun located in Olokemeji and Lisa villages, Ogun State. A total of eighteen water samples were collected for physicochemical analysis during high rainfall (May, June and July), low rainfall (August, September and October) and dry season (November and December) with mean rainfall values of 163.17, 88.03 and 8.95 mm, respectively, in both tributaries. Physicochemical parameters such as temperature (oC), electrical conductivity (EC), pH, total solids (TS), dissolved oxygen (DO), biochemical oxygen demand (BOD), total suspended solids (TSS), hardness (H), sulphate (SO4), phosphate (PO4), alkalinity, acidity, nitrate (NO3) and total dissolved solids (TDS) were analysed using standard laboratory methods. Digestive enzymes were analysed using 1 g of frozen gut of Simulium larvae grounded with 20 ml of 0.067 g of potassium hydrogen and 20 ml of 0.1 M sodium reagent. A total of 766 and 482 samples of Simulium larvae were collected from Olokemeji and Lisa tributaries using Eppendorf tubes. The zooplanktons collected from Olokemeji and Lisa tributary were 904 and 802, while phytoplanktons collected from Olokemeji and Lisa tributary were 635 and 582 during the study period. Data obtained were analysed using both descriptive analysis and T-test. The results obtained for the physicochemical parameters were 28.7 °C, 137.5 µS/cm, 6.3, 248.1 mg/L, 58 mg/L, 108.8 mg/L, 90.8 mg/L, 2.24 mg/L, 2.24 mg/L, 30.76 mg/L, 42.35 mg/L, 1.99 mg/L, 2.07 mg/L and 2.55 mg/L for Temperature, EC, pH, TS, DO, BOD, TSS, H, SO4, PO4, alkalinity, acidity, NO3 and TDS, respectively. There were significant (p < 0.05) differences between the means of EC, pH, TS, TDS, TSS and hardness of Lisa tributary, and water samples were also viewed under an electron microscope for zooplanktons and phytoplanktons. The values of species diversity which were greater than 0.5 indicated that the species were abundant and evenly distributed. There were significant (p < 0.05) differences between the tributaries in all the digestive enzymes except amylase content. The regression analysis between TSS, nitrate, sulphate, phosphate, acidity, hardness, TS, pH and Simulium larvae abundance showed a positive correlation, R2 with values of 0.828, 0.994, 0.948, 0.933, 0.986, 0.997, 0.889 and 0.981, respectively. The R2 values between Simulium larvae abundance with phytoplanktons and rainfall have values of 0.868 at p < 0.01 and 0.911 at p < 0.05.

The Content and Toxicological Risk Assessment of Trace Elemental Impurities (Pb and Cr) in Snacks from Ogun State, Southwestern Nigeria.

The monitoring of food contamination by trace elemental impurities (TEIs) are major health challenges in developing countries. The present study evaluated the content and toxicological risk assessment of TEIs in commonly consumed snack/junk foods from Ogun State, Nigeria. TEIs (Pb and Cr) were determined in sixty snack food samples purchased from Ijebu Ode, Ogun State, southwestern Nigeria. The TEIs were analysed in quadruplicates using atomic absorption spectrometry with flame atomization. TEI data were subjected to simple descriptive and inferential statistics. The toxicological risk assessment of TEIs was evaluated for hazard quotient (HQ), hazard index (HI) and cancer risk (CR) using the United States Environmental Protection Agency-Integrated Risk Information System (USEPA-IRIS) model. Data showed the varying Pb levels of 8.22 ± 1.57 mg/kg in sausage to 12.25 ± 4.27 mg/kg in cocoyam chips higher than the permissible limit of the Codex Alimentarius of the Joint World Health Organization and Food and Agriculture Organization. The toxicological risk assessment revealed the HQs greater than 1.0 for Pb and Cr in most snack foods consumed by adults and children, indicating adverse health problems. The CRs of Pb (children) and Cr (adults and children) also breached the acceptable limit of 1.0 × 10-4, signifying possible lifetime development of cancer. It is therefore necessary to periodically monitor the TEIs in snacks to protect the public health.

Organochlorine pesticide residues in Uganda's honey as a bioindicator of environmental contamination and reproductive health implications to consumers.

Honey has multifaceted nutritional and medicinal values; however, its quality is hinged on the floral origin of the nectar. Taking advantage of the large areas that they cover; honeybees are often used as bioindicators of environmental contamination. The focus of the present paper was to examine the quality of honey from within the vicinity of an abandoned pesticide store in Masindi District in western Uganda. Surficial soils (<20 cm depths) and honey samples were collected from within the vicinity of the abandoned pesticide store and analysed for organochlorine pesticide (OCP) residues using gas chromatograph coupled to an electron capture detector (GC-ECD). The mean level of ∑DDTs in all the soil samples was 503.6 µg/kg dry weight (d.w). ∑DDTs contributed 92.2% to the ∑OCPs contamination loads in the soil samples, and others (lindane, aldrin, dieldrin, and endosulfans) contributed only 7.8%. Ratio (p, p'-DDE+p, p'-DDD)/p, p'-DDT of 1.54 suggested historical DDT input in the area. In all the honey samples, the mean level of ∑DDTs was 20.9 µg/kg. ∑DDTs contributed 43.3% to ∑OCPs contamination loads in the honey samples, followed by lindane (29.8%), endosulfans (23.6%) and dieldrin (3.2%), with corresponding mean levels of 14.4, 11.4 and 1.55 µg/kg, respectively. Reproductive risk assessment was done based on the hazard quotient (HQ) and hazard index (HI) procedure. In our study, the calculated HIs for adults (102.38), and children (90.33) suggested high potential health risks to the honey consumers. Lindane, endosulfan and p, p'-DDD detected in the honey samples at levels exceeding the acute reference dose (ARfD) are known risk factors for spontaneous abortion, reduced implantation, menstrual cycle shortening, impaired semen quality, and prostate cancer in exposed individuals and experimental animal models.

Effects of industrialization on groundwater quality in Shagamu and Ota industrial areas of Ogun state, Nigeria.

In recent years, there has been an increasing ecological and global public health concern associated with environmental contamination by heavy metals on groundwater resources especially in the developing countries. Hence, this study assessed the impacts of industrialization on the quality of groundwater in Shagamu and Ota industrial areas of Ogun State, Nigeria between the period of July and December 2018, covering both wet and dry season. A total of 80 samples was collected from the industrial areas while a total of four control samples was also collected from the residential areas of the study locations across both wet and dry season using a random sampling technique. The water samples were then analyzed in the laboratory for their physico-chemical parameters (using standard procedures) and heavy metals using the Atomic Absorption Spectrophotometer (AAS). The results were evaluated for descriptive and inferential statistics using SPSS for Windows version 20.0. The mean range of values for the measured parameters was: pH (4.35-9.42), EC (18.50-684.0 µScm-1), hardness (3.83-396.06 mg/L), Ca2+ (0.18-138.75 mg/L) and that of heavy metals concentrations in the water sample were: Pb (0.003-0.199 mg/L), Cd (0.002-0.013 mg/L), Ni (0.004-0.259 mg/L), Cr (0.002-0.54 mg/L), Mn (0.015-1.940 mg/L), Fe (0.02-2.01 mg/L), Cu (0.012-0.72 mg/L), Zn (0.004-0.500 mg/L). A comparison of the obtained results with the World Health Organization standards (for drinking water) revealed that the levels of pH, Ca, Pb, Ni, Mn, Fe, Cd, and Cr were higher than the prescribed values. It was observed that groundwater sources for the dry season in both Ota and Shagamu have higher heavy metal concentrations that are above the permissible limits than the wet season, implying that more industrial activities were probably conducted during the dry season under the sampling period. The result of the heavy metals was in the magnitude according to the trend Fe > Mn > Cu > Cr > Zn > Ni > Pb > Cd. This study revealed that these industrialized areas contained high concentrations of heavy metals which can cause health disorders and behavioral defects. Thus, the water in the study locations is not suitable for consumption without prior treatment. It is therefore, recommends that the water in the study locations should be treated before were used for various domestic purposes, and the construction of the boreholes and dug wells are proposed here to follow proper siting regulations.

Health Risk Assessment of Metals in Selected Drinks from Abeokuta, Southwestern Nigeria.

The present study assessed the human health risk of metals in selected drinks from Abeokuta, southwestern Nigeria. Fifteen different brands of drinks (alcoholic, non-alcoholic, herbal and non-herbal) were purchased from notable markets in Abeokuta between June and August, 2018. A total of sixty drink samples were analysed for metals using atomic absorption spectrophotometry. Data were subjected to descriptive and inferential statistics. Human health risks were assessed for cancer risk (CR) and non-carcinogenic indices of hazard quotient (HQ) and hazard index (HI). Results showed acidic medium for most of the samples ranging from 3.12 ± 0.29 to 6.14 ± 0.17. The highest concentrations of Fe (5.53 ± 2.81 mg/L) and Mn (6.63 ± 8.33 mg/L) were found in Kunnu and Zobo, respectively. The HQ and HI values of Cu in bottled water indicated non-carcinogenic adverse effects, while the CR of Co in bottled water and bitters demonstrated carcinogenic effects. Regular monitoring of metals in drinks from the study area is recommended.

A review of environmental and health effects of organochlorine pesticide residues in Africa.

Organochlorine pesticides (OCPs) are generally categorized as chlorinated cyclodienes, chlorodiphenylethanes, chlorinated benzenes and cyclohexanes. The presence of OCP residues in foodstuffs, water, soil, sediments, blood serum and air has generated a surge of global interest. This is due to their severe environmental and health ill-effects. OCPs are characteristically described as persistent and bio-accumulating substances prone to long-range transportation. The aim of this present study is to assess the environmental and health risks associated with OCP residues. Published works on OCPs in surface water, sediments and fish samples were reviewed. Possible non-carcinogenic (Hazard Quotient, HQ and Hazard Index, HI) and carcinogenic (Cancer Risk, CR) health effects of OCPs were assessed in fish samples. High concentrations of OCP residues were determined in environmental samples from African countries. The non-carcinogenic health assessment of OCPs in most fish samples from Nigeria revealed HI values greater than 1.0 establishing their adverse effects. The CR data of OCPs in fish samples also showed values higher than the permissible standard of 1.0 × 10-4 indicating possible development of cancer through fish consumption.