The screening of hundreds of substances belonging to multiple chemical classes in liver is required in areas such as food safety or biomonitoring. We adapted a previous QuEChERS-based method in blood to the liver matrix and applied to these fields of study. The validation of the method allowed the inclusion of 351 contaminants, 80% with a LOQ < 2 ng/g. In the analysis of 42 consumer liver samples, we detected trace levels of 29 different contaminants. The most frequent and concentrated was 4,4’-DDE. POPs accounted for 66% of the compounds detected. In no case was the MRL reached for any of the contaminants detected. We also applied the method to 151 livers of wild birds to perform a biomonitoring pilot study in the Canary Islands. We detected 52 contaminants in 15 bird species. These were also mostly POPs, although high frequencies and concentrations of anticoagulant rodenticides (AR) and some other agricultural pesticides also stand out. POPs and AR contamination levels were significantly higher in terrestrial birds, raptors and particularly in nocturnal birds. Pesticide contamination levels were also higher in terrestrial birds, as well as in non-raptors and diurnal birds. The validated method is simple, robust, and sensitive and performs well in a variety of practical scenarios, where it can be carried out relatively quickly and inexpensively.

The recent volcanic eruption on the island of La Palma has aroused the concern of banana producers and consumers, given that in its area of influence there are thousands of hectares of banana plantations with an annual production of about 100 million kilos for export. Since volcanoes are one of the main natural sources of heavy metal contamination, we sampled bananas from the affected area and determined the concentrations of 50 elements (Ag, Al, As, Au, Ba, Be, Bi, Cd, Ce, Co, Cr, Cu, Cu, Dy, Er, Eu, Fe, Ga, Gd, Hg, Ho, In, La, Lu, Mn, Mo, Nb, Nd, Ni, Os, Pb, Pd, Pm, Pr, Pt, Sb, Sc, Se, Sm, Sn, Sr, Ta, Tb, Th, Ti, Tl, Tm, U, Y, Yb and Zn). The levels of 36 elements were elevated but the washing implemented after the eruption can remove a good part. After the washout, bananas have elevated levels of Fe, Al, Ti, V, Ba, Pb, most of the rare earth elements, Mo, and Co. In all cases, except Mo, the elevation is much higher in the peel than in the flesh. In the case of Mo, the elevation in banana flesh would translate into a higher nutritional intake of this trace element, which could represent up to 35% of the daily nutritional requirements. Exposure to toxic or potentially toxic elements, does not represent a health risk, since would not exceed 5% of the tolerable daily intake, even in the worst-case scenario.

Dry feed for pets lacks specific legislation regarding maximum residue limits for inorganic elements. The aim of the present study was to determine the content of 43 inorganic elements in dog and cat feed, studying whether there were differences according to the supposed quality of the food and performing the risk assessment for health. Thirty-one and thirty packages of pelleted dry food for cats and dogs, respectively, were analyzed. After acidic microwave-assisted digestion, elements were detected and quantified by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). In general, we did not observe important differences in the content of elements according to the supposed quality of the brand. Among trace elements, selenium and manganese are above the dietary reference value. Arsenic and mercury showed the highest acute hazard indexes, which make them risk factors for the health of dogs and cats. Aluminum, uranium, antimony and vanadium contents were above the toxic reference value and showed the highest acute hazard indexes. It is necessary to improve the legislation regarding the food safety of pets, for their health and to protect the rights of consumers.

Animal poisoning is one of the greatest conservation threats facing wildlife. In a preliminary study in the oceanic archipelago of the Canary Islands, we showed that the degree of threat from this circumstance was very high-even higher than that reported in other regions of continental Europe. Consequently, a legal framework for the effective prosecution of the crime of wildlife poisoning came into force in 2014 in this region. We present the results of the investigation of 961 animals and 84 baits sent to our laboratory for the diagnosis of animal poisonings during the period 2014–2021. We were able to identify poison as the cause of death in 251 animals and 61 baits. Carbofuran stands out as the main agent used in this archipelago. We have also detected an increasing tendency to use mixtures of several pesticides in the preparation of baits. The entry into operation of two canine patrols has led to the detection of more dead animals in the wild and a greater number of poisoned animals. The percentage of poison positives is significantly higher in areas with lower population density, corresponding to rural environments, as well as in areas with greater agricultural and livestock activity.

International Public Health authorities recommend biomonitoring studies to assess the exposure to chemicals in the general population. The aim of the present study was to analyze the blood concentrations of a total 360 pollutants, including 230 pesticides in current or recent use, 59 persistent organochlorine pollutants (POPs), 11 anticoagulant rodenticides and 60 pharmaceutical active compounds (PhACs), in a cohort of 403 subjects from Cape Verde. The study was performed in the frame of the Pesticide Residues in Vegetables of the Macaronesia project (PERVEMAC-II). A total of 60 out of 360 toxic compounds (16.7%) were detected, at least, in one participant. The three most frequently detected substances were p,p'-DDE (100%), phenanthrene (94.0%) and hexachlobenzene (35.9%). 2-Phenylphenol and imidacloprid were detected in 29.0 and 14.4% of the population. The three substances with the highest serum concentrations were PhACs: naproxen (249.1 ng/mL), metronidazole (115.6 ng/mL) and acetaminophen (25.2 ng/mL). Median blood concentration of p,p'-DDE, HCB and phenanthrene were 1.87, 0.08 and 0.36 ng/mL. Blood concentrations of POPs were influenced by age, although both gender and body mass index may exert an influence in the presence of these substances. Lifestyle has an effect on the concentration of these substances, especially in terms of dietary habits. Both the frequency of detection and the concentration of the studied substances are similar to those of other biomonitored populations. This is the first biomonitoring study carried out in Cape Verde. Our results may be useful for the implementation of public health measures by the competent authorities.

La Graciosa, a Natura 2000 site in the Canary Islands, faces substantial conservation challenges, including a large free-roaming cat population that threatens the island’s native biodiversity. In July 2024, a Trap–Neuter–Return (TNR) campaign achieved an 81.4% sterilization rate within urban areas, highlighting TNR’s short-term effectiveness in reducing reproductive potential and, consequently, mitigating predation pressures primarily through the prevention of new litters and reduced reproductive activity in cats. The campaign’s success relied heavily on the active involvement of the local community, who assisted with identifying, trapping, and monitoring free-roaming cats, thereby facilitating a high sterilization rate. However, administrative restrictions hindered access to peri-urban zones, leaving essential population clusters unsterilized and limiting the campaign’s overall scope. Additionally, strong opposition from conservation groups, amplified by extensive media coverage, halted the project prematurely, reducing the effective sterilization rate to 69.3% within three months. Population Viability Analysis (PVA) suggests that achieving high sterilization rates could lead to population reduction over time; however, the inability to access all population segments and to reach the ideal 93–95% sterilization threshold limits TNR’s potential as a long-term standalone solution. Our findings underscore the need for adaptive, context-specific management frameworks in ecologically sensitive areas that integrate TNR with complementary measures, consider regulatory barriers, and value community involvement. This case study provides crucial insights for policymakers and conservationists seeking to balance biodiversity conservation with humane management practices in protected areas.