Monitoring heavy metal contamination on the Iranian coasts of the Persian Gulf using biological indicators: risk assessment for the consumers

This research was conducted to determine the concentration of heavy metals (Cu, Pb, and Ni) in the sediments as well as the gill and muscle tissue of Siganus javus and two species of algae (Padina australis and Sargassum vulgare) collected from the Persian Gulf coasts of Bushehr province, which were studied using standard laboratory methods. The general form and trend of metal uptake at different stations in the gill and muscle tissue was Cu > Ni > Pb. The results of the study of metal uptake in both algae showed that the uptake of all three metals was higher in Padina species (Pb ˂ Cu ˂ Ni). The estimated daily intake (EDI), estimated weekly intake (EWI), allowable fish consumption rate limit (CR_lim), and the target hazard quotients (THQ) for the consumption of this fish were also calculated. It was found that the concentration of heavy metals in the edible parts of the fish did not exceed the permissible limits proposed by the WHO, MAFF, JECFA, and NHMRC for human consumption, but the Ni concentration was higher than standard. The consumer risk indexes for non-cancerous diseases due to all metals were lower than standard. Also, the total risk index (HI) in this study was 0.065.

Climate change adaptation and water saving by innovative irrigation management applied on open field globe artichoke

The setting up of innovative irrigation water management might contribute to the mitigation of negative issues related to climate change. Our hypothesis was that globe artichoke irrigated with a traditionally drip system could be converted to an innovative water management system based on precision irrigation techniques and on evaporative cooling application in order to improve crop physiological status with positive impacts on earliness, total heads yield and water saving. Over two experiments carried out at plot- and field-scale, two irrigation management systems, differing in type and application time, were compared: (i) conventional, and (ii) canopy-cooling. Plant physiological status at a weekly sampling interval and the head atrophy incidence (as the ratio of the total primary heads collected) were monitored. We also recorded and determined heads production, and yield components. In both experiments, throughout the application period of evaporative cooling (three months), canopy-cooling showed the lowest value of leaf temperature and the highest photosynthesis values compared with the conventional one (+3 °C and -30%, respectively). The physiological advantage gained by the crop with evaporative cooling has led to a higher production both in terms of total yield (+30%), and in terms of harvested first order heads that from an economic viewpoint are the most profitable for farmers. At farm-scale, the canopy-cooling treatment resulted in a higher earliness (35 days) and water productivity (+36%) compared with conventional one. Our findings show that by combining evaporative cooling practice with precision irrigation technique the heads yield can be optimized also leading to a relevant water saving (-34%). Moreover, the study proved that canopy-cooling set up might be a winning strategy in order to mitigate climatic changes and heat stress conditions.