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Emission of Polycyclic Aromatic Hydrocarbon compounds from combustion of crop residue was investigated. Crop residues comprising maize cobs, maize husks, rice husks and bean chaff were burnt in a furnace at a temperature of 400 °C and the emissions from the combustion process were characterized using standard methods. Health risk through inhalation was assessed using toxic equivalent factors and excess lifetime cancer risk. The results showed the detection of 16 PAH compound which included: Benzo[ghi]perylene, Naphthalene, Acenaphthene, Anthracene, Phenanthrene, Fluorene, Fluoranthene, Acenaphthylene, Pyrene, Benzo[a]anthracene, Dibenzo[a,h]anthracene, Benzo[b]fluoranthene, Chrysene, Benzo[a]pyrene, Indene[1,2,3-cd]pyrene and Benzo[k]fluoranthene. Benzo[b]fluoranthene had highest mean concentration of 1.30 μg/mg while Dibenzo[a,h]anthracene had the lowest mean concentration of 0.01 μg/mg. It was also revealed that the toxicity of PAHs was due to the presence of Benzo[b]fluoranthene for all the samples except for sample 4 for which the main contribution to toxicity was emission from benzo(a)pyrene, while the cancer risk assessment estimated to be 1.2 × 10

A mixture of gases and obnoxious odours are major components of landfill emission. A dispersion modelling on air pollutants and odour emissions anticipated from a proposed Integrated Waste Management Facility was conducted considering five operating scenarios. Impacts of the predicted ground level concentrations of air pollutants (including carbon monoxide, CO; oxides of nitrogen, NO(X); sulphur dioxide, SO(2); particulate matter, PM and hydrocarbons, HC) and odour on ambient air quality were investigated using the 10-min 1 OU/m(3) odour limit, CH(4) Lower Explosive Limit (LEL) and the daily limits of CO, NOx, SO(2), PM and HC. The anticipated maximum ground level concentration of emitted odour and CH(4) are 0.0040 OU/m(3) and 0.0349 ppm, respectively. Simultaneous operations of all the major components of the facility will generate the daily maximum concentrations of 7.34, 2.60, 7.31, 29.72 and 0.42 μg/m(3), for CO, NO(X), SO(2,) PM and HC, respectively. Generally, the facility impacts on ambient air quality will be within the acceptable limit.

Simulated accidental releases of chlorine from the premises of a major household products manufacturing company in Nigeria were investigated, with Threat Zones (TZs). The Aerial Location of Hazardo...

Cough and sneeze droplets’ interactions with indoor air of a typical hospital clinic that could be majorly found in developing African countries were studied to investigate the effectiveness of existing guidelines/protocols being adopted in the control of the widespread coronavirus disease (COVID-19) transmission. The influences of indoor air velocity, the type, size distribution, residence time in air, and trajectory of the droplets, were all considered while interrogating the effectiveness of physical distancing measures, the use of face covers, cautionary activities of the general public, and the plausibility of community spread of the SARS-CoV-2 virus through airborne transmission. Series of 3-D, coupled, discrete phase models (DPM) were implemented in the numerical studies. Based on DPM concentration maps as function of particle positions and particle residence times that were observed under different droplets release conditions, the virus-laden droplets could travel several meters away from the source of release (index patient), with smaller-sized particles staying longer in the air. The behavior of indoor air was also found to indicate complex dynamics as particle transports showed no linear dependence on air velocity. Supplementary Information The online version contains supplementary material available at 10.1007/s40201-020-00606-5.

The study assessed the impacts of abattoir activities on ambient air quality and health risk associated with exposure to PM2.5 and PM10, H2S, SO2 and NH3. Air samplings were done simultaneously around the abattoir at three points for sixty consecutive days (October to November) and standard methods adopted for the samplings and analysis. Health risks associated with exposure to PM10 and PM2.5 were estimated, using attributable fractions, relative risk and the excess lifetime cancer risk. The non-carcinogenic risks induced by the inhalation of H2S, SO2 and NH3 were also evaluated using hazard quotient (HQ). The results indicated that the average concentrations of 18.75 μg/m3, 89.17 μg/m3 and 0.1ppm for PM2.5, PM10 and NO2 respectively, were higher than the World Health Organization (WHO), National Ambient Air Quality Standard (NAAQS) and Federal Ministry of Environment (FMEnv) permissible limits. Air Quality Index showed that the ambient air quality in respect of CO and NH3 was very good, moderate for PM10 and was very poor for NO2 and SO2. It was also shown that 0.32% of deaths from lung cancer, and 0.23% from cardiopulmonary could be avoided if PM2.5 is reduced to 3 μg/m3 and while about 0.14% of all-cause mortality could be avoided if PM10 is reduced to 10 μg/m3. In similar manner, at least 0.45% likelihood that an individual in a group of people exposed to PM2.5 100m away from the burning point may have health issue (lung cancer) than an individual from another set of people that is exposed to baseline concentration of 3 μg/m3. All the HQ values exceeded the threshold value, set at the unity, implying that H2S, SO2 and NH3 are likely to cause adverse health effects in the area. Conclusively, continuous operation of this abattoir within the residential area can constitute a great environmental menace to the residents of the area and can result in complication to those with existing health challenge., Abattoir; Air quality; Particulate matter (PM); Air quality index; Dispersion; Cancer, Environmental chemical engineering; Atmospheric chemistry; Environmental analysis; Environmental health; Environmental impact assessment; Environmental risk assessment, Environmental science, Chemistry, Chemical engineering.

This study investigated the status of air quality at Olushosun, Abule Egba, and Solous dumpsite in Lagos, Nigeria. The parameters examined are total suspended particulates (TSP), CO, NO2, SO2, and odour. The Landfill Gas Emissions Model (LandGEM) was used to estimate the potential landfill gas emissions from the dumpsites. Sulphur dioxide (SO2) was not detected at Olushosun and Abule Egba dumpsites. At Solous, the measured concentration is about 21-folds of the 1-h limit with 24-h concentration of 0.09 ppm which is about ninefolds of the FMENV’s set limit. The measured concentrations of NO2 are about 1.3-folds of the set limit at all the locations in Olushosun and Abule Egba but between 2.5 and 5.0-folds at Solous. In Olushosun, the measured 1-h CO concentrations range between 8.0 and 40 ppm, at Abule Egba and Solous, the range is 10.0–44.0 ppm and 1.0–179.0 ppm, respectively. At Olushosun, the 1-h TSP concentration is about 2.5-folds of the 1-h limit but 3.2-folds and 2.8-folds of the same limit at both Abule Egba and Solous, respectively. The odour levels from the three dumpsites are significantly high ranging between 4 and 5 on the “intensity by word” scale of 5. The measured air quality parameters concentrations signify a badly impaired airshed and can be classified as having poor air quality which calls for urgent attention. The methane potential using the LandGem tool is estimated to be between 4.04 × 102 and 4.97 × 104 ton/year which is equivalent to about 6.06 × 105 to 7.45 × 107 m3/year. This can be used to generate about 0.4–49 MW of electricity if efficiently captured.

Background: Malaria in pregnancy is a major public health problem in Nigeria. Long-Lasting Insecticidal Nets (LLINs) have been advocated as an effective tool against malaria transmission. However, success of this intervention largely depends on the knowledge and practices regarding malaria and its prevention. Unfortunately, few studies have been done on effect of malaria preventive education on use of LLIN in pregnancy. Objective: To assess the knowledge of malaria and determine the effect of malaria preventive education on the use of LLINs among pregnant females in a Teaching Hospital in Osun state. Method: It was a one group pre-test post-test quasi - experimental hospital based study involving pregnant females attending Ante-Natal Clinic (ANC) of the Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC). A total of 200 respondents were recruited for this study by 2-stage sampling technique. Data was collected using a pretested questionnaire to elicit information on socio-demographic characteristics, use of LLIN in pregnancy, knowledge of malaria and its preventive measures. The data collected was analysed using descriptive and inferential statistics. The descriptive statistics comprised frequency, percentage, means and standard deviations. Bivariate analysis comprised Chi-square test on knowledge of malaria before and after intervention while correlation test assessed strength of relationship between knowledge of malaria preventive education and use of LLINs before and after intervention. Multivariate analysis determined the predictors of LLINs use. Analytical statistics of cross tabulation was conducted considering a p