Portable and stationary electrical generators became quite popular in Iraq soon after the shortage in national electrical
energy after 2003. Multi step risk assessment process is used in this study in the assessment of risks caused by
contamination of indoor air by lead particles emitted from domestic electrical generators. Two portable electrical
generators are tested under controlled indoor conditions (Radial LG (0.9 keV) fueled with benzene and oil and TigMax
(3 keV), fueled with benzene only). Lead particles in air were sampled by using portable dust sampler (Sniffer, L-30).
The atmospheric particulate sampling process is carried out in a flat located in the first floor of a three stories building
located in Baghdad city, Al-Zafarania region. The lead concentration in the digested filter papers is measured by using
atomic absorption spectrophotometer (Buck, USA). Dose-to-risk conversion factor is applied in this study to estimate the
potential cancer risk to Baghdad’s population related to continuous inhalation of airborne lead at the mean observed
concentrations. The results of toxicity analysis indicate that public exposure to airborne lead at the mean observed
concentration of 4.991 g/m3 can increase the risk of cancer at a rate of 12 extra cancer cases in a group of million
exposed individuals. Males are found to be at greater risk than females because of higher inhalation rates. Children are
found to be the most sensitive group due to low body weight (about 101 expected additional cancer cases in a group of
million exposed child).
Risk Assessment Due to Population Exposure to Lead Particles Emitted from Domestic Electrical Generators
lead
electrical generators
Publication Date
Fri Mar 01 2019
Journal Name
Applied Acoustics
Theoretical model of absorption coefficient of an inhomogeneous MPP absorber with multi-cavity depths
Micro-perforated panel (MPP) absorber has been known as an alternative absorber to classical porous material given its facile installation
long durability
environmental friendliness and attractive appearance. Extensive studies of MPP absorber proposing the improvement of its absorption frequency bandwidth have been published. This study presents a MPP absorber introduced with inhomogeneous perforations and with multi-cavity depths. The MPP is divided into two sub-area
where each area has different hole diameter
perforation ratio and a separated backed cavity depth. The acoustic impedance is modelled using electrical equivalent circuit and the absorption coefficient is calculated under normal-incidence of sound. It is found that the inhomogeneous MPP can have good bandwidth of absorption by designing the sub-MPP of smaller perforation ratio with large hole diameter and the one having the larger perforation ratio with smaller hole diameter. The absorption bandwidth can be conveniently controlled by adjusting the cavity depth of each sub-MPP. The results from the experimental work show good agreement with the theoretical model.
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