Continual increases in the human population and growing concerns related to the energy crisis, food security, disease outbreaks, global warming, and other environmental issues require a sustainable solution from nature. One of the promising resources is cyanobacteria, also known as blue-green algae. They require simple ingredients to grow and possess a relatively simple genome. Cyanobacteria are known to produce a wide variety of bioactive compounds. In addition, cyanobacteria’s remarkable growth rate enables its potential use in a wide range of applications in the fields of bioenergy, biotechnology, natural products, medicine, agriculture, and the environment. In this review, we have summarized the potential applications of cyanobacteria in different areas of science and development, especially related to their use in producing biofuels and other valuable co-products. We have also discussed the challenges that hinder such development at an industrial level and ways to overcome such obstacles.

Per- and polyfluoroalkyl substances (PFAS) belong to a group of synthetic compounds that have recently raised concerns about human health and environmental quality due to their great prevalence, degradation resistance, and potential toxicity. This review focuses on the applications of PFAS and their effects on human health. Specific emphasis has been laid on (i) the application/use of PFAS, (ii) sources and distribution of PFAS in diverse environmental compartments, and (iii) the impact of PFAS on human health. Significant health effects on humans are associated with exposure to PFAS, i.e., immunotoxicity, thyroid and kidney disorders, cancer, etc. Conclusions obtained from PFAS studies demonstrate that inadequate evidence should not be used to justify delaying risk reduction steps for PFAS alternatives. PFAS can be determined in different environmental matrices using both traditional analytical approaches, i.e., liquid chromatography coupled with mass spectrometry (LC-MS/MS) and semi-quantitative and passive sampling, and advanced analytical methods with colorimetric, spectrofluorimetric, and electrochemical detection. Traditional methods are costly and not broadly available, while the emerging, cost-effective methods are less sensitive and unable to meet regulatory exposure limits. There is still a significant number of studies to be performed to fully comprehend the real contamination by PFAS.

Nutrient management is always a great concern for better crop production. The optimized use of nutrients plays a key role in sustainable crop production, which is a major global challenge as it depends mainly on synthetic fertilizers. A novel fertilizer approach is required that can boost agricultural system production while being more ecologically friendly than synthetic fertilizers. As nanotechnology has left no field untouched, including agriculture, by its scientific innovations. The use of nanofertilizers in agriculture is in the early stage of development, but they appear to have significant potential in different ways, such as increased nutrient-use efficiency, the slow release of nutrients to prevent nutrient loss, targeted delivery, improved abiotic stress tolerance, etc. This review summarizes the current knowledge on various developments in the design and formulation of nanoparticles used as nanofertilizers, their types, their mode of application, and their potential impacts on agricultural crops. The main emphasis is given on the potential benefits of nanofertilizers, and we highlight the current limitations and future challenges related to the wide-scale application before field applications. In particular, the unprecedent release of these nanomaterials into the environment may jeopardize human health and the ecosystem. As the green revolution has occurred, the production of food grains has increased at the cost of the disproportionate use of synthetic fertilizers and pesticides, which have severely damaged our ecosystem. We need to make sure that the use of these nanofertilizers reduces environmental damage, rather than increasing it. Therefore, future studies should also check the environmental risks associated with these nanofertilizers, if there are any; moreover, it should focus on green manufactured and biosynthesized nanofertilizers, as well as their safety, bioavailability, and toxicity issues, to safeguard their application for sustainable agriculture environments.