Analysis of Indoor Radon Level and its Health Risks Parameters in Three Selected Towns in Port Harcourt, Rivers State, Nigeria

Analysis of indoor radon level and its health risk parameters has been carried out in Borikiri (BT), Diobu (DR), and Rebisi (RB) towns in Port Harcourt, Rivers State, Nigeria. A pocket sized Corentium Arthings digital radon detector meter was used to record the indoor radon concentration levels. The geographical coordinates were recorded using a hand-held geographical positioning system (GPS) for the various sample points. A total of ten houses were measured for each town making a total of 30 sample points for the three communities. The results obtained show that for Borikiri town, the concentration level varied from 30.7100 - 19.9800 Bqm-3 with an average of 11.32 ± 2.59 Bqm-3 . The annual absorbed dose varied from 7.7478 - 1.1202 mSv/yr with a mean value of 2.59 ± 0.65 mSv/yr while the annual equivalent dose rate varied from 0.829 - 0.336 mSv/yr with an average of 0.69 ± 0.16 mSv/yr The excess life time cancer risk calculated for seventy years (70yrs) varied from 6.510 - 0.941 with an average of 2.45 ± 1.71. The results of the indoor concentration level for Diobu town ranged from 37.74 - 5.9200 Bqm ?3 with a mean value of 12.95 ± 2.91 Bqm-3 . The annual absorbed dose for the area ranged from 9.5214 - 1.1494 with an average of 3.26 ± 0.73 mSv/yr, the annual equivalent dose rate varied from 0.694-0.359 with a mean of 0.78±0.8, the excess life time cancer risk calculated for seventy years ranged from 8.000-1.725 with a mean of 2.91±0.61. The indoor concentration level for Rebisi town ranged from 12.9500?4.0700 Bqm-3 with an average of 8.55 ± 1.00, the annual absorbed dose ranged from 3.2671 - 1.0268 mSv/yr, the annual equivalent dose rate varied from 0.784 - 0.269 with an average of 0.52 ± 0.06, the excess life time cancer risk of 2.745 - 0.863 with an average of 1.82 ± 0.21. The results of the indoor concentration levels, the annual absorbed dose and the annual effective dose rate are all below the ICRP safe limit. However, the results of the excess life time cancer risk are all higher than the ICRP safe standard limit of 0.029 × 10-3 .

Evaluation of Indoor Radon and It’s Health Risks Parameters within Azuabie, Trans-Amadi and Nkpogu Towns, in Port Harcourt, Rivers State, Nigeria

Evaluation of indoor radon level and its health risk parameters has been carried out in three communities Azuabie, Trans-Amadi and Nkpogu towns in Port Harcourt, Rivers State, Nigeria. A pocket sized Corentium Arthings digital radon detector meter was used to record the indoor radon concentration levels. The geographical coordinates were recorded using a hand-held geographical positioning system (GPS) for the various sample points. A total of 30 sample points were evaluated, with 10 sample points for each town respectively. The results of the concentration levels showed that for Azuabie (AZ) town, the concentration level varied from 6.660 Bqm-3 to 13.690 Bqm-3 with an average of 10.65±0.95Bqm-3. Nkpogu (NK) town the results of the indoor concentration level ranged from 9.250 Bqm-3 to 18.870 Bqm-3 with an average of 13.32±1.02 Bqm-3, Nkpogu (NK) town, the indoor concentration level ranged from 7.030 Bqm-3 to 20.350 Bqm-3 with an average of 12.25±1.34Bqm-3. The annual absorbed dose for Azuabie, Trans-Amadi and Nkpogu varied as follows, 1.680 mSvy-1 – 3.921 mSvy-1, 2.334 mSvy-1 – 47610 mSvy-1 and 1.774 mSvy-2 – 5.134 mSvy-1 respectively. The annual effect dose rate for the three towns ranged from 0.403 mSvy-1 – 0.941mSvy-1, 0.560 mSvy-1 - 1.143 mSvy-1 and 0.426 mSvy-1 – 1.143mSvy-1. The excess life time cancer risk varied from 1.4117 – 3.294, 1.9607 – 3.999 and 1.4901 – 3.999 respectively. The results of the indoor concentration levels annual and the absorbed dose and the annual effective dose rate are all below the ICRP safe limit. However, the results of the excess life time cancer risk are all higher than the ICRP safe standard limit of 0.029×10-3.

Field Survey on Concentration and Emission of Dust in Different Types of Poultry Houses of South Korea

The dust generated from poultry houses has an adverse effect on farmers and poultry in terms of hygiene and welfare problems. However, there is little information on concentration and emission of dust derived from poultry houses located in South Korea. An objective of this study is to provide fundamental data regarding particulate matters generated from the poultry houses situated in South Korea. A total 27 poultry houses, including nine broiler houses, nine layer houses, and nine layer houses with feces conveyors were surveyed. Dust was measured by gravimetric methods. Emission of dust was calculated by multiplying the mean concentration (mg/m3) measured at the center of the poultry house by the ventilation rate (m3 h−1). Mean indoor concentrations of total and respirable dust in poultry houses were 4.39 (SD: 2.38) mg/m3 and 2.33 (SD: 2.21) mg/m3, respectively. Mean emission rates based on area and rearing number were estimated as 3.04 (±1.64) mg head−1 h−1 and 57.48 (±24.66) mg m−2 h−1 for total dust and 2.34 (±1.27) mg head−1 h−1 and 26.80 (±10.81) mg m−2 h−1 for respirable dust, respectively. The distribution of total and respirable dust between indoor concentration and emission rate was a similar pattern, regardless of type of poultry house. Among types of poultry house, the broiler house showed the highest levels of indoor concentration and emission rate, followed by the layer house with feces conveyor belt, and the caged layer house. In terms of seasonal aspect, indoor concentrations of total and respirable dust were highest in winter and lowest in summer, and their emission rates were the opposite at all the poultry houses. In spring and autumn, both indoor concentration and emission rate were moderate, and there was no significant difference between spring and autumn. It was assumed that the levels of indoor concentration and emission rate of dust generated from poultry houses were determined mainly by use of bedding material and ventilation rate among various environmental agents.

Influence of the lateral source/building separation on vapour intrusion: A numerical study

Various vapour intrusion (VI) models have been proposed in order to predict indoor concentration of Volatile Organic Compounds (VOCs) in buildings. However, these models tend to be conservative, and overestimate or underestimate vapour flux emissions due to several assumptions. Particularly, most of these VI models only consider an infinite uniform contaminated groundwater as the principal source of VOCs in the soil, and lateral pollution source in the vadose zone are disregarded. It has been shown that ignoring the lateral source position may lead to uncertainties on the estimations. In this paper, a numerical model is developed in order to better understand the relationship between the lateral source position in the soil, including both a source in the vadose zone and a source located at the groundwater level, and the resulting indoor air concentration. Results show that source position plays a significant role on vapour intrusion attenuation. In fact, indoor concentration of VOCs decreases with increasing lateral separation. Finally, it is shown that considering the source position can significantly improve the quality of VI predictions.

Correlates of Indoor Concentration of Carbon Monoxide in Residential Buildings in Gondar Town, Northwest Ethiopia

This community-based cross-sectional study was conducted to investigate the indoor concentration of carbon monoxide (CO) and associated factors in residential buildings of Gondar town, northwest Ethiopia. Data were collected from 384 occupied buildings and occupants using CO meter, interviewers administered questionnaire, and observation checklists. Multivariable binary logistic regression analysis was used for controlling the possible effect of confounders and to identify factors associated with indoor concentration of CO on the basis of adjusted odds ratio (AOR) with 95% confidence interval (CI) and P < .05. The current study revealed that 224(58.3%) occupied buildings had the concentration of CO above the permissible value for 15 minute exposure for living rooms (100 mg/m3). Indoor concentration of CO was significantly associated with access to health information [AOR = 0.081, 95%CI = (0.008, 0.803)], number of rooms [AOR = 0.016, 95% CI = (0.001, 0.279)], area of occupied room [AOR = 0.019, 95% CI = (0.001, 0.237)], buildings located away from main roads/garages [AOR = 0.045, 95% CI = (0.005, 0.415)], clean energy sources [AOR = 0.010, 95% CI = (0.001, 0.123)], presence of separate kitchen [AOR = 0.030, 95% CI = (0.004, 0.221)], no incensing in the room [AOR = 0.055, 95% CI = (0.006,0.499)] and measurements in the afternoon [AOR = 0.114, 95% CI = (0.013, 0.965)]. Residents, therefore, need to use clean energy sources, construct a kitchen with a properly constructed chimneys away from the main building, and avoid incensing inside the indoor environment.