This paper investigates the energy bounds in modified GaussBonnet gravity with anisotropic background. Locally rotationally symmetric Bianchi type I cosmological model in f (R, G) gravity is considered to meet this aim. Primarily, a general f (R, G) model is used to develop the field equations. In this aspect, we investigate the viability of modified gravitational theory by studying the energy conditions. We take in account four f (R, G) gravity models commonly discussed in the literature. We formulate the inequalities obtained by energy conditions and investigate the viability of the above mentioned models using the Hubble, deceleration, jerk and snap parameters. Graphical analysis shows that for first two f (R, G) gravity models, NEC, WEC and SEC are satisfied under suitable values of anisotropy and model parameters involved. Moreover, SEC is violated for the third and fourth models which predicts the cosmic expansion.

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The main purpose of this paper is to investigate energy bounds in the context of f (R, G) gravity. To meet this aim, we choose static spherically symmetric spacetime in f (R, G) gravity to develop the field equations. We select three different models of f (R, G) gravity, which are thoroughly discussed in the literature. Firstly, the inequalities are formulated using energy bounds and then viability of the considered models are checked respectively. Graphical analysis show that specific f (R, G) gravity models are satisfied under suitable values of model parameters. It is shown that in a certain case energy bounds are satisfied expect SEC, which supports the late time acceleration expansion of unverse.

IntroductionC admium is highly toxic element abundantly found in nature, and an important component of earth layer (crust) including soil, water, air, underground soil, mines, plant tissues, animal tissues, and ores. Cadmium may cause adverse effects on human, animal and plants health especially when its concentration exceeds the limit due to continuous produc-tion. Cadmium ranges in earth crust between 0.1 to 0.5 ppm, in marine Because of high environmental and human health concerns, a lot of research has been done over the past 50 years. Sources of Cd emission are both natural and anthropogenic (manmade). Total Cd emission from natural sources ranges from 10-50% (Morrow et al., 1995;Nawrot et al., 2006). Mining activities are the biggest source of Cd emission in environment and contaminate soil, air, water Abstract | Cadmium (Cd) is highly toxic metal which naturally exists in environment in small proportion but continuously increasing due to anthropogenic activities. The rapid increase in population is putting pressure on urbanization, agriculture and industrialization which have resulted in gradual increase in Cd level. It is released from industries as an impurity and pollutes soil, water and air in different ways. High solubility in water increases its mobility in the soil ecosystem. The use of sludge and chemical sprays on crops increase the Cd contamination besides some other heavy metals. Through nutrient cycling, it is taken up from the soil to plants and finally becomes the part of human body which warrants serious health concerns. Cadmium causes mild to severe effects on plants, animals and environmental health. Humans are exposed to cadmium through food, water intake, inhalation (cigarette) and dermal contact which then produces heart disease, kidney failure, lung cancer, orthopedic disease, nervous system failure, low immunity level, mental retardation and growth retardation. Different environmental friendly and low cost biological remedies are used nowadays to control Cd toxicity such as phytoremediation phytostabilisation, rhizofilteration, phytoextraction. This review paper has summarized the impact of Cd on soil, plants and humans and strategies to remove or minimize its toxicity by applying some low cost and environmental friendly techniques.