Total mercury (THg), methylmercury (MeHg), and selenium (Se) concentrations were measured in various commercially important fish species. The benefit–risk binomial associated with these chemicals was assessed in children through the probability of exceeding the provisional tolerable weekly intakes (PTWIs) of the contaminants and the Se recommended dietary allowance (RDA). The Se:Hg molar ratios, selenium health benefit values (HBV_Se), and monthly consumption rate limits (CR_mm) for each species were also calculated. THg and Se were analyzed by atomic absorption spectrophotometer (Shimadzu, Milan, Italy), while MeHg was determined by Trace Ultra gas chromatograph connected with a PolarisQ MS (Thermo Fisher Scientific, Waltham, MA, USA). None of the analyzed fish had Hg levels above the European Community regulatory limits, while most large predators had MeHg levels over the threshold concentration set by US EPA. The estimated weekly intakes of THg and MeHg exceeded in many cases the PTWIs and the Se estimated daily intakes were provided from 0.71% to 2.75% of the RDA. Se:Hg molar ratios above 1 and positive HBV_Se index suggested that Se in fish could be enough to alleviate the potential toxic effect of Hg. However, high-risk groups as children should consume fish in moderation because a large consumption pattern, especially of swordfish and tunas, might be of concern for health.

This study examined the effect of different crude protein (CP) levels in the diet on growth performance of broilers as well as the total aerobic mesophilic count (TAMC) and Escherichia coli count (ECC) isolated from chicken faeces. A total 150 day-old broilers (Hubbard) were allocated to three treatments with five replicates containing 10 birds. The dietary treatments consisted of three diets with different CP levels for 42 days: high-protein (HCP, 22.5%), medium-protein (MCP, 20.5%), and low-protein (LCP, 18.5%). Body weight and feed intake were determined and the feed conversion ratio was calculated. Faecal samples were collected at 14, 21 and 42 days. Dietary CP did not affect the growth performance of broilers. Reducing CP level was effective at beneficially modulating the composition of the faecal microflora, in particular TAMC and ECC concentrations (log ₁₀ CFU g ⁻¹ ) were significant lower for the LCP birds. During hot temperature conditions (33°C and 70% relative humidity) a low protein diet may help to control the characteristics of the faecal microbial community without negative effects on broiler performance.

Trace element (Hg, Pb, Cd, Zn, Cu, Ni, and Cr) occurrence was determined in the muscle tissue of swordfish collected in the Mediterranean Sea to assess whether the intakes complied with the recommended levels for essential metals and permissible levels for toxic elements. Metals were analyzed by an atomic absorption spectrophotometer (Shimadzu AA 7000). The methodology of Target Hazard Quotient (THQ) was also evaluated. The ranking order of toxic metal concentration was Hg > Cd > Pb, while for essential elements the distribution pattern followed the sequence Zn > Cu > Ni > Cr. The Estimated Weekly Intakes (EWI) as well as THQ for Cd and Pb indicated that swordfish consumption did not pose a risk to human health, whereas the major concern was for Hg. Fish size-related changes in Hg concentrations resulted in high EWI and THQ values relative to larger fish consumption, implying a potential risk to human health. For consumer protection, catches of swordfish approximately above 44 kg should be avoided as these fish have a higher risk of containing toxic levels of Hg.