Ecological pollution features and health risk exposure to heavy metals via street dust and topsoil from Nkpor and Onitsha in Anambra, Nigeria.

The manuscript presents the investigation results on the pollution and risk of metal mines, and it is considered an important report on environmental pollution near mines in Nigeria, with archival value. The research involved soil sampling and heavy metal analysis for about 12 months in three metal mines. Based on these results, the paper provides information on pollution levels and hazards using well-known methods like pollution and ecological risk indexes. The increasing population in urban communities attracted by various industrial, economic and social activities causes contamination of atmospheric environment that can affect human health. We investigated heavy metal distributions, correlation coefficient among elements, ecological indices and probable health risk assessment in street dust and topsoil from Nkpor and Onitsha urban suburb, Nigeria. The mean concentration of heavy metals in car dust from Onitsha and Nkpor suburb follows thus: Fe > Mn > Cu > As > Pb > Ni > Cr. The decreasing trend of heavy metal in rooftop dust from both area: Fe > Mn > Cu > Pb > As > Ni > Cr whereas metal contents in topsoil were: Fe > Mn > Cu > Pb > Ni > Cr > As for both areas. The degree of pollution indices was characterized by contamination factor (CF), geo-accumulation factor (I-geo), pollution load index (PLI), Nemerow (PN), ecological and potential ecological risk index (ER and PERI) which indicated low pollution in the urban street environment. The results of Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) showed that the estimated heavy metals displayed sources from atmospheric deposition, natural origin and anthropogenic sources. Risk assessment revealed that ingestion of dust and soil was the significant route for heavy metals exposure to the populace followed by inhalation, then dermal contact. Considering all factors, non-cancer risk was more prominent in children than adults and no significant health hazard could be attributed to both aged groups as of the period of study except for As and Ni that needs constant monitoring to avoid exceeding organ damaging threshold limit of 1 × 10-4.

Hematological, biochemical, and biometric changes in Clarias gariepinus exposed to antipsychotic drug chlorpromazine.

Chlorpromazine (CPZ) is a neuroleptic and antipsychotic medication for individuals suffering from schizophrenia and other medical conditions. This study investigated the effects of CPZ on the hematological, biochemical, and biometric characteristics in juvenile Clarias gariepinus. The fish were exposed to 0.53, 1.06, and 2.11 mgL-1 CPZ for 15 days after which they were withdrawn from the toxicant and allowed to recover for 5 days. Blood were sampled from the fish on days 1, 5, 10, 15, and during the 5-day recovery for hematological and biochemical analysis, and thereafter, the fish were sacrificed for the morphometric analysis. While the values of the white blood cells significantly increased in the exposed fish, the hemoglobin, red blood cells, and packed cell volume decreased. Compared with the control, there were no significant differences in the values of the blood derivatives in the exposed fish. The values of protein and glucose reduced, but those of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase were significantly elevated. Though there was no significant difference in the condition factor, a significant increase in hepatosomatic index occurred on day 15 at 5.28 mg/L CPZ. After the 5-day withdrawal from the drug, most of the studied parameters returned to the control values. The present study indicated that CPZ is toxic to fish and should be used with utmost care to guard against toxicological effect on non-target organisms.

Chemometric and risk assessment of nitrogen composition of atmospheric rainwater from diverse surfaces in Rivers State, Nigeria.

Organic and inorganic nitrogen ions in the environment play important role across environmental matrices. Rainwater samples collected from ambient and different roofing surfaces (zinc, aluminium, asbestos and stone-coated roofing sheets) from selected locations at Ogale, Rumuodomaya/Rumuodome, Diobu and Chokocho within Rivers State, Niger Delta, Nigeria, from April to June, July to August and September to October depicting three regiments of early, mid and late rains. The samples were analysed for Kjeldahl nitrogen, ammonium, nitrate and nitrite using APHA methodology. Quantitative assessment showed that Kjeldahl nitrogen were in range of 0.11 to 28.05 mg/L; ammonium 0.50 to 20.22 mg/L, nitrate from 0.12 to 22.69 mg/L and nitrite from 0.15 to 3.90 mg/L. Parameters decreased from early to late rain, which can be attributed to rain dilution factor potential, wind pattern and emission from anthropogenic sources that influenced the rainwater quality across surfaces. Nitrogen results showed that dry and wet deposition has great impact; atmospheric aerosols and biogeochemical interactions can affect water quality. Monthly variation showed that Ogale had high regression compared to other locations due to close proximity to oil and gas emission and marine contribution. Neutralization factor showed that nitrate-nitrite compounds have strong correlation with ammonium ion. Non-carcinogenic risk assessment using US EPA model showed hazard index less than one (1), thus no associated health effect of nitrate and nitrite in rainwater. In conclusion, it is evident that nitrate/nitrite levels and other nitrogen derivatives in rainwater in crude oil-producing Niger Delta and its continuous consumption can cause negative health outcome.

Chemometrics, health risk assessment and probable sources of soluble total petroleum hydrocarbons in atmospheric rainwater, Rivers State, Nigeria.

Total petroleum hydrocarbons (TPHs)-(aliphatic and aromatic) were analysed for in atmospheric rainwater between April-June; July-August; September-October depicting early, mid, late rain of 2019. Sampling at Rumuodomaya/Rumuodome and Ogale in Rivers State using basins fastened to a Table 2M above ground and 120 M from high features, Rainwater was analysed after treatment using Agilent GC-FID. Results show cumulative TPHs at R/R were 56.6551 mg/L, 39.5201 mg/L and 7.2283 mg/L, Ogale: 9.1217 mg/L, 59.4923 mg/L and 21.9825 mg/L. Aliphatic hydrocarbons: C5-C8 were < 1, low contamination, other carbon aggregates (C9-C16, C17-C35, and C36-C40) indicate high contamination. Chemometric assessment showed high contamination. TPHs aggregates at Rumuodomaya/Rumuodome were-C8-C11 (1.034 and 1.005) early rain, C18-C25 and C26-C33 has Carbon preference index of 1.287 and 1.630 (mid-rain), C26-C33 has CPI of 1.288 (late-rain), Ogale area, C26-C33 has CPI of 1.732 (early-rain), mid-rain C8-C11 (2.768) and C12-C17 (5.368). Pristane/phytane ratio indicated biogenic and pyrogenic sources. Average carbon length of TPHs for odd n-alkanes were C9-C11 (9.446) and C35-C39 (38.980), C9-C11(10.238), C35-C39 (36.510); C9-C11 (10.240) and C35-C39 (36.934). Average daily intake depicted possible health issues for children and adults as hazard index > 1 for aromatics.

Morphometric, hematological and oxidative stress changes in Clarias gariepinus following sub-chronic exposure to tramadol.

Tramadol is among the most famous analgesic drugs used for the management, treatment and relief of moderate to severe pain conditions. The present study investigated the effects of tramadol on the behavior, mortality, morphometric, hematology and oxidative stress parameters of C. gariepinus juveniles. The 96 h LC50 value of tramadol determined by probit analysis was 88.76 mg/L. Based on this value, fish were exposed to sublethal concentrations of 4.44, 8.88, 17.75 mg/L tramadol and 0.0 mg/L (control) for the period of 15 days and allowed to recover for 5 days. Fish exposed to tramadol showed some abnormal behavioral responses and mortality increased with increase in the exposure duration and concentrations except for the control. There were variations in hepatosomatic index (HSI) and condition factor (CF) in fish exposed to tramadol. Exposure of C. gariepinus to tramadol elicited reduction in the values of white blood cell (WBC), red blood cell (RBC), hemoglobin (Hb), packed cell volume (PCV) and mean corpuscular volume (MCV) while the values of mean corpuscular hemoglobin (MCH) and the mean corpuscular hemoglobin concentration (MCHC) increased. The values of catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), reduced glutathione (GSH) and lipid peroxidation (LPO) increased significantly in the exposed fish compared with the control. The values of glutathione peroxidase (GPx) however decreased. The results of the present study demonstrate that tramadol is toxic to fish and its use should be monitored in the aquatic environment.

Hazards and risk assessment of heavy metals from consumption of locally manufactured painkiller drugs in Nigeria.

In the informal sector of Nigeria's economy, jobs are done manually as against automation resulting in body stress and pain, hence the need for painkiller drugs. Thirty different locally manufactured painkiller drugs, with analgesic, antipyretic and anti-inflammatory effects, were randomly sampled from pharmaceutical shops within Awka in October 2016. The drugs were pulverised, sieved and ashed before digestion using conc aqua regia HCl : HNO3 (3:1), carcinogenic heavy metals (arsenic, cadmium, chromium, mercury, nicked and lead) were assayed using Varian AA240 atomic absorption spectrophotometer (AAS). Risk assessment was carried out using US EPA model. The highest levels of arsenic (0.350 mg/kg) were found in samples with code 01, 03 and 020, cadmium (0.107 mg/kg and 0.144 mg/kg) were in samples code 013 and 028, and samples 03 and 011 had chromium levels as 6.637 mg/kg and 5.298 mg/kg. Highest value of mercury (0.470 mg/kg) was in sample code 01. All the painkiller drugs have nickel in the range of 0.046-0.448 mg/kg while highest values of lead were in sample code 05, 025 and 029 as 2.47 mg/kg, 1.11 mg/kg and 1.16 mg/kg. Non-cancer risk ranged as As (Nd -1.60 × 10-3), Cd (Nd-1.97 × 10-4), Cr (Nd-6.06 × 10-6), Hg (Nd-2.15 × 10-4), Ni (9.93 × 10-6-3.34 × 10-5) and Pb (Nd-4.36 × 10-4) while the cancer risk were As (Nd-1.63 × 10-7), Cd (Nd-4.45 × 10-9), Cr (Nd-1.56 × 10-7), Hg (Nd -1.53 × 10-9), Ni (1.50 × 10-10 -1.46 × 10-9) and Pb (Nd-8.82 × 10-9). The total cancer risk (TCR) and total non-cancer risk (TNCR) for all the heavy metals were in the range of 7.21 × 10-13-1.25 × 10-10 and 1.51 × 10-7-5.56 × 10-5 respectively. The TCR was below 1 × 10-6 -1 × 10-4 range while TNCR for heavy metals was below 1; the values established by US EPA. In conclusion, continuous consumption of locally Nigerian made painkiller drugs may expose the subjects to heavy metal toxicity.

Health risk assessment of cadmium, chromium and nickel from car paint dust from used automobiles at auto-panel workshops in Nigeria.

Nigeria's economic problems which inhibited local production has resulted in massive importation of used automobiles. Most of these automobiles need some repairs and reworking, having outlived their lifespan in the manufacturer's country. This study centers on the human carcinogenic and non-carcinogenic health risk assessment of cadmium, chromium and nickel exposures from reworking of imported used vehicles. Scraped car paint dusts from 56 Japanese made cars were collected from 8 different panel beating (body works) workshops (A-H) in Southeastern Nigeria. They were homogenized, mixed, divided into fine particles, filtered and digested by standard method. The filtrates were assayed for cadmium, chromium and nickel with atomic absorption spectrophotometry (AAS, 200A), workshops F and D have the highest concentration (mg/kg) of Cd (3.58 ± 0.02) and (3.36 ± 0.04) and higher than levels in workshops A, B, C, E, G and H. Chromium (mg/kg) in workshops F and G were (2.87 ± 0.04) and (2.95 ± 0.06) and higher than the other workshops. Nickel in workshop A (3.84 ± 0.04) is close to other workshop values. The highest hazard quotients for adults were cadmium in workshops B (1.37E-01), D (1.69E-01), E (1.79E-01) (inhalation), chromium [workshops G (5.45E-02), F (5.29E-02) and C (5.24E-02) inhalation]. Nickel -workshop A (5.9E-03) for children (inhalation). HQ in children through ingestion is cadmium (3.72E-04) workshop F and ingestion- 3.21E-01(workshop F) while nickel is 1.06E-02 (workshop A).The highest cancer risks were in exponents -4,-7 and -8 (adult) and -3, -6 and -9 (children) for workshops A-H through inhalation, ingestion and dermal contact, exposures to scrap car paint dust may be of significant public health importance in Nigeria as it can add to body burden of some carcinogenic heavy metals.