Health risk-benefit assessment of the commercial red mangrove crab: Implications for a cultural delicacy.

Mangrove forests, provide vital food resources and are an endangered ecosystem worldwide due to pollution and habitat destruction. A risk-benefit assessment (RBA) was performed on the red mangrove crab (Ucides occidentalis) from the threatened Guayas mangroves in Ecuador. It was aimed to assess the combined potential adverse and beneficial health impact associated with crab consumption and define a recommended safe intake (SI) to improve the diet of the Ecuadoran population while ensuring safe food intake. Target hazard quotients (THQs), benefit quotients (Qs), and benefit-risk quotients (BRQs) were calculated based on the concentrations of the analyzed contaminants (121 pesticide residues, 11 metal(loid)s, antimicrobial drugs from 3 classes) and nutrients (fatty acids, amino acids, and essential nutrients). Except for inorganic arsenic (iAs), the THQ was below 100 for all investigated contaminants, suggesting that the average crab consumer is exposed to levels that do not impose negative non-carcinogenic or carcinogenic health effects in the long and/or short term. Concentrations of iAs (average AsIII: 25.64 and AsV: 6.28 µg/kg fw) were of the highest concern because of the potential to cause negative health effects on long-term consumption. Despite the thriving aquaculture in the Guayas estuary, concentrations of residues of the antimicrobial drugs oxytetracycline (OTC), florfenicol, and nitrofurans still were low. Based on the fact that different risk reference values exist, related to different safety levels, four SI values (0.002, 0.04, 4, and 18 crabs/day) were obtained. The strictest intake values indicate a concern for current consumption habits. In conclusion, the red mangrove crab contains various important nutrients and can be part of a balanced diet for the Ecuadorian population when consumed in limited portions. The present study emphasizes the importance of safeguarding the quality of the environment as a prerequisite for procuring nutritious and safe food.

A state-of-the-art review on cadmium uptake, toxicity, and tolerance in rice: From physiological response to remediation process.

Cadmium (Cd), a major contaminant of concern, has been extensively reviewed and debated for its anthropogenic global shifts. Cadmium levels in rice grains raise wide food safety concerns. The aim of this review is therefore to capture the dynamics of Cd in paddy soil, translocation pathways of Cd from soil to consumption rice, and assess its bio-accessibility in human consumption. In crop plants, Cd reduces absorption of nutrients and water, triggers oxidative stress, and inhibits plant metabolism. Understanding the mechanisms and behaviour of Cd in paddy soil and rice allows to explain, predict and intervene in Cd transferability from soil to grains and human exposure. Factors affecting Cd movement in soil, and further to rice grain, are elucidated. Recently, physiological and molecular understanding of Cd transport in rice plants have been advanced. Morphological-biochemical characteristics and Cd transporters of plants in such a movement were also highlighted. Ecologically viable remediation approaches, including low input cost agronomic methods, phytoremediation and microbial bioremediation methods, are emerging.

Speciation, transportation, and pathways of cadmium in soil-rice systems: A review on the environmental implications and remediation approaches for food safety.

Cadmium (Cd) contamination in paddy fields is a serious health concern because of its high toxicity and widespread pollution. Recently, much progress has been made in elucidating the mechanisms involved in Cd uptake, transport, and transformation from paddy soils to rice grains, aiming to mitigate the associated health risk; however, these topics have not been critically reviewed to date. Here, we summarized and reviewed the (1) geochemical distribution and speciation of Cd in soil-rice systems, (2) mobilization, uptake, and transport of Cd from soil to rice grains and the associated health risks, (3) pathways and transformation mechanisms of Cd from soil to rice grains, (4) transporters involved in reducing Cd uptake, transport, and accumulation in rice plants, (5) factors governing Cd bioavailability in paddy, and (6) comparison of remediation approaches for mitigating the environmental and health risks of Cd contamination in paddy fields. Briefly, this review presents the state of the art about the fate of Cd in paddy fields and its transport from soil to grains, contributing to a better understanding of the environmental hazards of Cd in rice ecosystems. Challenges and perspectives for controlling Cd risks in rice are thus raised. The summarized findings in this review may help to develop innovative and applicable methods for controlling Cd accumulation in rice grains and sustainably manage Cd-contaminated paddy fields.

A critical review on effects, tolerance mechanisms and management of cadmium in vegetables.

Cadmium (Cd) accumulation in vegetables is an important environmental issue that threatens human health globally. Understanding the response of vegetables to Cd stress and applying management strategies may help to reduce the Cd uptake by vegetables. The aim of the present review is to summarize the knowledge concerning the uptake and toxic effects of Cd in vegetables and the different management strategies to combat Cd stress in vegetables. Leafy vegetables grown in Cd contaminated soils potentially accumulate higher concentrations of Cd, posing a threat to food commodities. The Cd toxicity decreases seed germination, growth, biomass and quality of vegetables. This reduces the photosynthesis, stomatal conductance and alteration in mineral nutrition. Toxicity of Cd toxicity also interferes with vegetable biochemistry causing oxidative stress and resulting in decreased antioxidant enzyme activities. Several management options have been employed for the reduction of Cd uptake and toxicity in vegetables. The exogenous application of plant growth regulators, proper mineral nutrition, and the use of organic and inorganic amendments might be useful for reducing Cd toxicity in vegetables. The use of low Cd accumulating vegetable cultivars in conjunction with insolubilizing amendments and proper agricultural practices might be a useful technique for reducing Cd exposure in the food chain.

Cadmium and zinc uptake by volunteer willow species and elder rooting in polluted dredged sediment disposal sites.

Salix species and Sambucus nigra L. (elder) naturally invade dredged sediment landfills and are commonly encountered on substrates contaminated with heavy metals. Foliar concentrations of Cd and Zn in four Salix species and elder were explored in the field. Metal contents in dredged sediment derived soils were elevated compared to baseline concentration levels reported for Flanders. To evaluate foliar concentrations, reference data were compiled from observations in nurseries, young plantations and unpolluted sites with volunteer willow vegetation. Willows grown on polluted dredged sediment landfills showed elevated foliar Cd and Zn concentrations (>6.6 mg Cd/kg DW and >700 mg Zn/kg DW). This was not the case for elder. For willow, a significant relation was found between soil total Zn or Cd and foliar Zn or Cd, regardless of age, species, or clone. Willows proved to be useful bioindicators. Results indicated a possible threat in long-term habitat development of willow brushwood from transfer of Cd and Zn to the food web.