Determination of nitrogen dioxide, sulfur dioxide, ozone, and ammonia in ambient air using the passive sampling method associated with ion chromatographic and potentiometric analyses

Concentrations of nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and ammonia (NH3) were determined in the ambient air of Al-Ain city over a year using the passive sampling method associated with ion chromatographic and potentiometric detections. IVL samplers were used for collecting nitrogen and sulfur dioxides whereas Ogawa samplers were used for collecting ozone and ammonia. Five sites representing the industrial, traffic, commercial, residential, and background regions of the city were monitored in the course of this investigation. Year average concentrations of ≤59.26, 15.15, 17.03, and 11.88 μg/m3 were obtained for NO2, SO2, O3, and NH3, respectively. These values are lower than the maxima recommended for ambient air quality standards by the local environmental agency and the world health organization. Results obtained were correlated with the three meteorological parameters: humidity, wind speed, and temperature recorded during the same period of time using the paired t test, probability p values, and correlation coefficients. Humidity and wind speed showed insignificant effects on NO2, SO2, O3, and NH3 concentrations at 95% confidence level. Temperature showed insignificant effects on the concentrations of NO2 and NH3 while significant effects on SO2 and O3 were observed. Nonlinear correlations (R2 ≤ 0.722) were obtained for the changes in measured concentrations with changes in the three meteorological parameters. Passive samplers were shown to be not only precise (RSD ≤ 13.57) but also of low cost, low technical demand, and expediency in monitoring different locations

Physiological and behavioural responses of broilers to controlled atmosphere stunning: implications for welfare

AbstractControlled atmosphere (gas) stunning (CAS) has the potential to improve the welfare of poultry at slaughter but there is a lack of consensus about which gas mixtures are most humane. The aim of this study was to evaluate the welfare consequences of different gas stunning approaches. Individual broilers were exposed to gas mixtures capable of inducing unconsciousness and euthanasia while their behavioural, cardiac, respiratory and neurophysiological responses were measured simultaneously. The approaches investigated included anoxia (N2or Ar with &lt; 2% residual O2), hypercapnic anoxia (30% CO2in Ar, 40% CO2in N2) and a biphasic method (40% CO2, 30% O2, 30% N2for 60 s followed by 80% CO2in air). Evaluation of the welfare implications of each approach centred on the likelihood of them inducing negative states or experiences during the conscious phase. Hypercapnic mixtures were associated with strong respiratory responses, while anoxic mixtures induced vigorous wing flapping. Electroencephalogram analysis using the correlation dimension (a non-linear measure of complexity) suggested that anoxic wing flapping occurred during periods in which a form of consciousness could not be excluded. Hypercapnic hyperoxygenation (biphasic approach) exacerbated respiratory responses but eliminated the possibility of vigorous behavioural responses occurring during a conscious phase. The relative importance of respiratory discomfort versus the potential to induce significant distress due to convulsive wing flapping and associated trauma is a matter for debate. We argue that respiratory discomfort is unpleasant but may be preferable to the risk of vigorous wing flapping and associated injury while conscious in poultry during CAS.</jats:p

Ammonia emissions in tunnel-ventilated broiler houses

Gas production in broiler houses and their emissions are closely related to the microclimate established inside the house according to air temperature, humidity, and velocity. Therefore, the internal house environment is influenced by building typology and ventilation system. The objective of the present study was to evaluate ammonia emission rates in broiler houses equipped with different ventilation systems (negative or positive pressure) and litter conditions (new or built-up). The environment of six commercial broiler houses was evaluated internal and external NH3 concentrations. Ventilation rates were recorded to estimate ammonia emission rates. The efficiency of circulation and exhaust fans was assessed, and higher ventilation rates were determined in negative-pressure houses due to the higher flow of the fans. Houses with new litter increased ammonia emission rates along the rearing period, indicating the relationship between gas emissions, bird age and ventilation rates, and presented a typical curve of NH3 emission increase. Negative-pressure houses with built-up litter presented higher emission rates during the first rearing week due to the high NH3 concentration during the brooding period, when the ventilation rates required to maintain chick thermal comfort are low. Although the results of the present study indicate an advantage of the positive-pressure systems as to gas emissions, further research is needed reduce gas emissions in broiler houses with negative-pressure systems

Ammonia in the atmosphere: A review on emission sources, atmospheric chemistry and deposition on terrestrial bodies

10.1007/s11356-013-2051-9Environmental Science and Pollution Research20118092-8131ESPL