Abstract: There are many situations in which human activities have significant effects on the environment. Damage to the ozone layer is one of them. The objective of this work is to use the Least Squares Method, considering the linear, exponential, logarithmic, power and polynomial models of the second degree, to analyze through the coefficient of determination (R²), which model best fits the behavior of the chlorodifluoromethane (HCFC-142b) in parts per trillion between 1992 and 2018, as well as estimates of future concentrations between 5 and 10 periods, i.e. the concentration of this pollutant in the years 2023 and 2028 in each of the adjustments. A total of 809 observations of the concentration of HCFC-142b in one of the monitoring stations of gases precursors of the deterioration of the ozone layer during the period of time studied were selected and, using these data, the statistical software Excel was used for make the scatter plots of each of the adjustment models. With the development of the present study, it was observed that the logarithmic fit was the model that best fit the data set, since besides having a significant R² its adjusted curve was compatible with the natural trend curve of the phenomenon.
Abstract: Ozone (O3) is considered as one of the most
phytotoxic pollutants with deleterious effects on living and non living
components of Ecosystems. It reduces growth and yield of many
crops as well as alters the physiology and crop quality. The present
study described series of experiments to investigate the effects of
ambient O3 at different locations with different ambient levels of O3
depending on proximity to pollutant source and ranged between 17
ppb/h in control experiment to 112 ppb/h in industrial area
respectively. The ambient levels in other three locations (King Saud
University botanical garden, King Fahd Rd, and Almanakh Garden)
were 61,61,77 ppb/h respectively. Tow legume crops species (vicia
vaba L ; and Pisum sativum) differ in their phenology and sensitivity
were used. The results showed a significant negative effect to ozone
on morphology, number of injured leaves, growth and productivity
with a difference in the degree of response depending on the plant
type. Visia Faba showed sensitivity to ozone to number and leaf area
and the degree of injury leaves 3, pisum sativum show higher
sensitivity for the gas for degree of injury 1,The relative growth rate
and seed weight, it turns out there is no significant difference
between the two plants in plant height and number of seeds.
Abstract: Air quality studies were carried out in the towns of
Putrajaya, Petaling Jaya and Nilai in the Malaysian Peninsular. In this
study, the variations of Ozone (O3) concentrations over a four year
period (2008-2011) were investigated using data obtained from the
Malaysian Department of the Environment (DOE). This study aims to
identify and describe the daily and monthly variations of O3
concentrations at the monitoring sites mentioned. The SPPS program
(Statistical Package for the Social Science) was used to analyze this
data in order to obtain the variations of O3 and also to clarify the
relationship between the stations. The findings of the study revealed
that the highest concentration of O3 occurred during the midday and
afternoon (between 13:00-15:00 hrs). The comparison between
stations also showed that highest O3 concentrations were recorded in
Putrajaya. The comparisons of average and maximum concentrations
of O3 for the three stations showed that the strongest significant
correlation was recorded in the Petaling Jaya station with the value
R2= 0.667. Results from this study indicate that in the urban areas of
Peninsular Malaysia, the concentration of O3 depends on the
concentration of NOx. Furthermore, HYSPLIT back trajectories
(-72h) indicated that air-mass transport patterns can also influence the
O3 concentration in the areas studied.