Investigation on the Storage Stability of Packaged Water Commonly Produced in Ilorin Metropolis, Kwara State, Nigeria

This study investigated the effects of storage conditions on the physicochemical parameter, microbial loads and health risks assessment of randomly 30 selected sachet and bottle water brands (A, B and C) in Ilorin Metropolis. Random sampling procedures were used to collect samples from three different brands and subjected to three different storage conditions; immediately (initial), mild sunlight and intense sunlight condition. The heavy metals (Cr, Pb and Fe) investigated in this study were above the permissible limits (WHO, SON). The presence of TBC, TCC, FCC and TFC in all the water samples analyzed showed no effective quality control system. Incremental lifetime cancer risk (ILCR) assessment revealed a carcinogenic health risk to the populace drinking this water. It can be deduced from this study that water stored under sunlight for a long period of time is not good for human consumption and therefore adequate monitoring by the appropriate agencies are emphasized.

Human Health Assessment of Sixteen Priority Polycyclic Aromatic Hydrocarbons in Contaminated Soils of Northwestern Algeria

Background. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental organic contaminants generated by incomplete combustion of organic materials that are widely distributed in soils. Objectives. This study represents the first attempt to examine the health toxicity of 16 detected PAHs in contaminated soil, via different exposure pathways to populations in northwestern Algeria. Methods. The toxicity equivalency quotients (TEQ) of PAHs were evaluated. The carcinogenic risk assessment of incremental lifetime cancer risk (ILCR) from ingestion, inhalation, and dermal exposure pathways to each PAH in soil are described. Results. Incremental lifetime cancer risk values were in the upper limit of the tolerable range (10−6–10−4) for adults and children. The total cancer risk of PAH-contaminated soils for children, adolescents and adults was 2.48×10−5, 2.04×10−5 and 3.12×10−5mg.kg−1d−1, respectively. The highest potential cancer risks were identified for adults and children, with adolescents having the lowest risks. Across exposure pathways, the dermal contact and ingestion pathways had the greatest contributions to the carcinogenic risk of human exposure to PAHs. Conclusions. Further research and guidelines are needed for risk assessments of PAHs in agricultural, residential/urban, and industrial areas, and further risk assessments should include risks posed by exposure through air. Competing Interests. The authors declare no competing financial interests.

Polycycl. Aromatic Hydrocarbon Exposure of Children in Typical Household Coal Combustion Environments: Seasonal Variations, Sources, and Carcinogenic Risks

Polycyclic aromatic hydrocarbon (PAH) emissions from the combustion of household solid coal for cooking and heating cause great harm to public health in China, especially in less developed areas. Children are one of the most susceptible population groups at risk of indoor air pollutants due to their immature respiratory and immune systems. However, information on PAH exposure of children is limited due to limited monitoring data. In this study, we aimed to assess the seasonal differences of PAHs in classrooms, analyze the pollutant sources, and calculate the incremental lifetime cancer risk attributable to PAHs in Shanxi Provence. A typical school using household coal combustion in Shanxi Province was selected. Fine particulate matter (PM2.5)samples were collected by both individual samplers and fixed middle-flow samplers during the heating and non-heating seasons in December 2018 and April 2019. The PAH concentrations in PM2.5 samples were analyzed by a gas chromatograph coupled to a mass spectrometer. The results showed that PAH concentrations in PM2.5 varied between 89.1 ng/m3 in the heating season and 1.75 ng/m3 in the non-heating season. The mean concentrations of benzo[a]pyrene (BaP), a carcinogenic marker of PAHs, were 10.3 and 0.05 ng/m3 in the heating and non-heating seasons, respectively. Source allocation analysis of individual portable and passive samplers revealed that the main contributors during heating and non-heating seasons were coal combustion and gasoline sources, respectively. According to the results of a Monte Carlo simulation, the incremental lifetime cancer risk values from the inhalation of PAHs in the heating and non-heating seasons were 3.1 × 10−6 and 5.7 × 10−8, respectively. The significant increase in PAHs and the incremental lifetime cancer risk in the heating season indicates that children are more exposed to health threats in winter. Further PAH exposure control strategies, including reducing coal usage and promoting clean fuel applications, need to be developed to reduce the risk of PAH-induced cancer.

Levels of Heavy Metals in Soya Bean and Some Cereal Samples from Shani and Kwayakusar Local Government Areas in Borno State, Nigeria

Grain (soya beans, sorghum and maize) samples from Shani and Kwayakusar Local Government Areas, Borno State, Nigeria were collected in agricultural locations for the determination of heavy metals. The levels of heavy metals were determined using Atomic Absorption Spectroscopy (AA–6800 SHIMADZU). The levels of all the heavy metals studied in all the agricultural locations were higher in the post-harvest grains than in the pre-harvest grains. Results from the Incremental Lifetime Cancer Risk (ILCR) showed that, there was the possibility of developing cancer related diseases from the consumption of cereal samples from the study area with respect to the 10-4 tolerable limit. The results further suggested that the source of these heavy metals content in the grains samples might be largely as a result of the application of agrochemicals. Hence, consumption of the study cereals from the study area is of health risk with respect to Pb, Cd and As and should be given higher priority by relevant agencies.