In many parts of the world, the agricultural sector is faced with a number of challenges including those arising from abiotic environmental stresses which are the key factors responsible for most reductions in agrifood production. Crude oil contamination, an abiotic stress factor and a common environmental contaminant, at toxic levels has negative impacts on plants. Although various attempts have been made to demonstrate the impact of abiotic stresses on crops, the underlying factors responsible for the effects of crude oil and its induced abiotic stresses on the composition of the stressed plants are poorly understood. Hence, this review provides an in-depth examination of the: (1) effect of petroleum hydrocarbons on plants; (2) impact of abiotic environmental stresses on crop quality; (3) mechanistic link between crude oil stress and its induced abiotic stresses; as well as (4) mode of action/plant response mechanism to these induced stresses. The paper clearly reveals the implications of crude oil-induced abiotic stresses arising from the soil-root-plant route and from direct application on plant leaves.
Total petroleum hydrocarbons (TPH) clean-up standards, intervention and/or target values, are designed to effectively manage introduction of toxic petroleum hydrocarbons into the environment. This research assessed the impact of some crude oil remediation intervention values, involving sub-lethal concentrations of crude oil, on yield and phytochemical contents of kale (Brassica oleracea L.) and lettuce (Lactuca sativa L.). Crude oil contamination within the range examined did not affect emergence; yield and phytochemical distributions were affected at some levels of contamination, particularly 10,000 mg•kg-1 TPH. There is the potential of TPH to moderate effects of crude oil at 10,000 mg•kg-1 to enhance contents of some phenolics and organic
The Emerging Concept of Nonpolypoid Colorectal NeoplasiaThe frequent occurrence of flat or nonpolypoid neoplastic colorectal lesions has been reported recently in the Japanese literature, and also now in Western countries. In the large series collected by S. Kudo [1 ± 3] at the Akita Red Cross Hospital in Japan, 45 % of early neoplastic lesions detected at colonoscopy were found to have a nonpolypoid morphology. The figure was only slightly lower (32 %) in the revisited results of the National Polyp Study in the USA [4]. In Japan, nonpolypoid lesions (adenoma or cancer) are classified as variants of superficial lesions of types 0-II, i. e. superficially elevated (0-II a), completely flat and flush with the surrounding mucosa (0-II b) or superficially depressed without frank ulcer (0-II c). In mixed types, both depression and elevation are present (II a + II c or II c + II a). Depressed lesions represent less than 5 % of all early neoplastic colorectal lesions.
Heavy crude oil spills have been recorded to have detrimental effects on the soil properties of agricultural lands and the eventual agricultural produce. However, the influence of sub-lethal concentrations of crude oil on crop quality is not clearly understood. Hence, the present study assessed the response of Micro-Tom tomato fruits to low concentrations of crude oil. Although the range of crude oil concentrations used in this research had no significant effect on most of the nutritional and phytochemical parameters tested, the growth, yield, fruit production and ripening of the Micro-Tom tomato fruits were affected at crude oil remediation intervention value (CRIV) of 5,000 mg/kg TPH.The usual trend of organic acids' distribution in tomatoes was also altered. The experimental results re-affirmed that apart from genetics, environmental factors -such as crude oil contamination -may influence tomato fruit quality and yield. Nonetheless, the research findings suggest that crude oil-contaminated sites at ≤ 3,000 mg/kg TPH presents a similar growing environment to a clean site for the cultivation of sensitive crops with reduced negative impact on crop quality.
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