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.

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.

The study assessed the impacts of abattoir activities on ambient air quality and health risk associated with exposure to PM 2.5 and PM 10 , H 2 S, SO 2 and NH 3 . 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 PM 10 and PM 2.5 were estimated, using attributable fractions, relative risk and the excess lifetime cancer risk. The non-carcinogenic risks induced by the inhalation of H 2 S, SO 2 and NH 3 were also evaluated using hazard quotient (HQ). The results indicated that the average concentrations of 18.75 μg/m 3 , 89.17 μg/m 3 and 0.1ppm for PM 2.5 , PM 10 and NO 2 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 NH 3 was very good, moderate for PM 10 and was very poor for NO 2 and SO 2 . It was also shown that 0.32% of deaths from lung cancer, and 0.23% from cardiopulmonary could be avoided if PM 2.5 is reduced to 3 μg/m 3 and while about 0.14% of all-cause mortality could be avoided if PM 10 is reduced to 10 μg/m 3 . In similar manner, at least 0.45% likelihood that an individual in a group of people exposed to PM 2.5 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/m 3 . All the HQ values exceeded the threshold value, set at the unity, implying that H 2 S, SO 2 and NH 3 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.

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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 < 0.05 to be statistically significant. Results: There was an increase in the scores of knowledge on malaria transmission after the intervention and this was statistically significant (χ 2 = 8.862, p < 0.01). Similarly, the scores of knowledge on malaria prevention increased after the intervention and this was statistically significant (χ 2 = 10.023, p < 0.01). Respondents' age, marital status and gravidity were predictors of LLINs use. Biserial correlation showed a statistically positive relationship between knowledge of malaria preventive education and use of LLINs after intervention ( r = 0.036, p < 0.01). Conclusion: The use of malaria preventive education was found to be effective in increasing the use of LLIN in this study. These findings highlight a need for educational intervention in implementation of LLINs. There is therefore a need to strengthen the policy of malaria prevention education as an integral component with distribution of free LLIN in health care setting to enhance its utilization.