Sperm Motility Impairment in Free Spawning Invertebrates Under Near-Future Level of Ocean Acidification: Uncovering the Mechanism

Ocean acidification (OA) refers to the decrease in ocean water pH resulting from the increasing absorption of atmospheric CO2. This will cause changes in the ocean's carbonate chemistry system with a resulting impact on reproduction of marine organisms. Reproduction is the fundamental process that allows the conservation of the species; in free-spawning marine invertebrates, this process is highly sensitive to changes in seawater quality and chemistry. To date, the majority of the studies concerned OA effects on reproduction has been focused on embryo and larval development. Despite several evidence for the impairment of reproductive success by environmental perturbations through altering gamete quality, sperm physiological responses to OA are poorly investigated. In this study, we evaluated the effects of exposure to acidified seawater (AcSW) (pH 7.8), which approximate the predicted global averages for oceanic surface waters at the end of this century, on sperm quality of the mussel Mytilus galloprovincialis and the ascidian Ciona robusta by evaluating several endpoints, such as motility, vitality, mitochondrial activity, oxidative state, and intracellular pH (pHi). Following sperm exposure to AcSW, the percentage of motile spermatozoa, mitochondrial activity and pHi decreased in comparison to the current seawater pH of 8.1, whereas vitality and oxidative state were unaffected by the low external pH in both the species. In broadcast spawners, a relationship between sperm intracellular pH and the initiation of motility are well known. Spermatozoa are immotile in the testes and motility is induced after the spermatozoa are released into seawater; the alkaline pH of seawater, in fact, increases the pHi activating motility and mitochondrial respiration. The results of this study suggest that the lowering of seawater pH as predicted to occur for 2100, through the inhibition of pHi increase, prevent sperm motility activation. Sperm motility is a key determinant of fertilization success; consequently, a corresponding drop in fertilization success would be expected with important implications for the fitness and the survival of marine invertebrates

Respiratory health in waste collection and disposal workers

Waste management, namely, collection, transport, sorting and processing, and disposal, is an issue of social concern owing to its environmental impact and effects on public health. In fact, waste management activities are carried out according to procedures that can have various negative effects on the environment and, potentially, on human health. The aim of our study was to assess the potential effects on respiratory health of this exposure in workers in the waste management and disposal field, as compared with a group of workers with no occupational exposure to outdoor pollutants. The sample consisted of a total of 124 subjects, 63 waste collectors, and 61 office clerks. Informed consent was obtained from all subjects before inclusion in the study. The entire study population underwent pulmonary function assessments with spirometry and completed two validated questionnaires for the diagnosis of rhinitis and chronic bronchitis. Statistical analyses were performed using STATA 13. Spirometry showed a statistically significant reduction in the mean Tiffenau Index values in the exposed workers, as compared with the controls, after adjusting for the confounding factors of age, BMI, and smoking habit. Similarly, the mean FEV1 values were lower in the exposed workers than in the controls, this difference being again statistically significant. The FVC differences measured in the two groups were not found to be statistically significant. We ran a cross-sectional study to investigate the respiratory health of a group of workers in the solid waste collection and disposal field as compared with a group of office workers. In agreement with most of the data in the literature, our findings support the existence of a prevalence of respiratory deficits in waste disposal workers. Our data suggest the importance of adopting preventive measures, such as wearing specific individual protection devices, to protect this particular category of workers from adverse effects on respiratory health

Ecotoxicological Assays with the Calanoid Copepod Acartia tonsa: A Comparison between Mediterranean and Baltic Strains

The use of marine invertebrates in ecotoxicology is important for an integrated approach which takes into consideration physiological responses and chemical levels in environmental matrices. Standard protocols have been developed and organisms belonging to different trophic levels are needed as model organisms to evaluate toxicant bioavailability and assess their impact on marine biota. The calanoid copepod Acartia tonsa is commonly used in ecotoxicology due to its widespread distribution and well-studied biology. However, different strains coming from various geographical areas are available, and possible variations in physiological characteristics raise concerns about the comparability of ecotoxicological results. This study compares the life cycle assessment and sensitivity of Adriatic and Baltic strains of A. tonsa exposed to nickel (Ni2+) in standardized acute and semi-chronic tests. Life cycle assessments revealed differences in egg production, egg-hatching success, and naupliar viability between the strains. The acute toxicity test demonstrated the significantly higher sensitivity of Adriatic strain nauplii to Ni2+ compared to the Baltic strain, whereas the semi-chronic test showed no significant difference in sensitivity between the strains. These findings suggest that while strain-specific differences exist in different geographical populations, responses to toxicants are not significantly different. Particularly, the semi-chronic assessments with both A. tonsa strains emphasized the robustness of this species as a model organism in ecotoxicology

Does salinity variation increase synergistic effects of triclosan and carbon nanotubes on Mytilus galloprovincialis? Responses on adult tissues and sperms

The use of carbon nanotubes (CNTs) is rapidly increasing and several scientific studies have addressed their toxicological properties. However, only a very small number of publications have deal with the interaction between CNTs and other molecules. Triclosan (TCS) is an antibacterial agent used in personal care and household products. Commonly detected in aquatic ecosystems, there is a strong evidence that aquatic biota is sensitive to this compound. Aside from emergent pollutants, aquatic organisms are continuously subjected to abiotic variations including salinities. Therefore, the main goal of the present study was to better understand how physio-chemical interactions of CNTs with TCS under different salinity levels (37, 28 and 19) affect the mussel species Mytilus galloprovincialis through the evaluation of biochemical alterations on gametes (sperms) and adult tissues, providing more ecologically relevant information on organisms' responses. The results showed toxicological effects in terms of sperm metabolic activity and intracellular reactive oxygen species production as well as cellular damage and alteration of metabolic capacity at the adult's stage when exposed to both contaminants acting alone and in combination, under tested salinities. Moreover, when the mussels were exposed to the combination of both contaminants, they showed major toxic impacts on both assessed biological levels (adult tissues and sperms) especially under control salinity. This suggests that toxicity upon mixture exposure compared to single-substance exposure may impair mussels' populations, affecting reproduction success and growth.publishe

Non-occupational exposure to heavy metals of the residents of an industrial area and biomonitoring

In areas at high environmental risk, a major issue is the assessment of the exposure of the general population to industrial pollutants. To date, few studies have investigated exposure to heavy metals in a population residing in a high risk environmental area. The aim of this study is to evaluate the exposure to heavy metals in the industrial area of Taranto, Southern Italy, through biological monitoring techniques. We measured the levels of inorganic arsenic and methylated metabolites, lead, cadmium, chromium, and manganese in the urine samples of 279 subjects residing in Taranto and neighboring areas. After obtaining informed consent from each participant, qualified health staff administered a standardized structured questionnaire investigating lifestyle habits and assessing any confounding factors. The biological monitoring data showed high urinary concentrations of nearly all of the heavy metals investigated. These findings could be related to the presence of industrial plants and is sufficient to warrant the expectation that local and national institutions should be required to adopt preventive measures to reduce the environmental exposure of the general population to heavy metals

Cumulative asbestos exposure and mortality from asbestos related diseases in a pooled analysis of 21 asbestos cement cohorts in Italy

Background: Despite the available information on cancer risk, asbestos is used in large areas in the world, mostly in the production of asbestos cement. Moreover, questions are raised regarding the shape of the dose response relation, the relation with time since exposure and the association with neoplasms in various organs. We conducted a study on the relationship between cumulative asbestos exposure and mortality from asbestos related diseases in a large Italian pool of 21 cohorts of asbestos-cement workers with protracted exposure to both chrysotile and amphibole asbestos. Methods: The cohort included 13,076 workers, 81.9% men and 18.1% women, working in 21 Italian asbestos-cement factories, with over 40 years of observation. Exposure was estimated by plant and period, and weighted for the type of asbestos used. Data were analysed with consideration of cause of death, cumulative exposure and time since first exposure (TSFE), and by gender. SMRs were computed using reference rates by region, gender and calendar time. Poisson regression models including cubic splines were used to analyse the effect of cumulative exposure to asbestos and TSFE on mortality for asbestos-related diseases. 95% Confidence Intervals (CI) were computed according to the Poisson distribution. Results: Mortality was significantly increased for ‘All Causes’ and ‘All Malignant Neoplasm (MN)’, in both genders. Considering asbestos related diseases (ARDs), statistically significant excesses were observed for MN of peritoneum (SMR: men 14.19; women 15.14), pleura (SMR: 22.35 and 48.10), lung (SMR: 1.67 and 1.67), ovary (in the highest exposure class SMR 2.45), and asbestosis (SMR: 507 and 1023). Mortality for ARDs, in particular pleural and peritoneal malignancies, lung cancer, ovarian cancer and asbestosis increased monotonically with cumulative exposure. Pleural MN mortality increased progressively in the first 40 years of TSFE, then reached a plateau, while peritoneal MN showed a continuous increase. The trend of lung cancer SMRs also showed a flattening after 40 years of TSFE. Attributable proportions for pleural, peritoneal, and lung MN were respectively 96, 93 and 40%

Micro(nano)plastics and plastic additives effects in marine annelids: a literature review

Plastic debris are dispersed in the marine environment and are consequently available to many organisms of different trophic levels, including sediment-dwelling organisms such as polychaetae. Plastic degradation generates micro (MPs) and nanoplastics (NPs) and as well as releases bounded plastic additives, increasing the ecotoxicological risk for marine organisms. Therefore, this review summarizes current knowledge on the accumulation and effects of MPs and NPs and plastic additives in polychaetes, derived from laboratory and field evidences. Thirty-six papers (from January 2011 to September 2021) were selected and analysed: about 80% of the selected works were published since 2016, confirming the emerging role of this topic in environmental sciences. The majority of the analysed manuscripts (68%) were carried out in the laboratory under controlled conditions. These studies showed that polychaetes accumulate and are responsive to this contaminant class, displaying behavioural, physiological, biochemical and immunological alterations. The polychaetes Hediste diversicolor and Arenicola marina were the most frequent used species to study MPs, NPs and plastic additive effects. The consideration of field studies revealed that MP accumulation was dependent on the plastic type present in the sediments and on the feeding strategy of the species. Polychaetes are known to play an important role in coastal and estuarine food webs and exposure to MPs, NPs and plastic additives may impair their behavioural, physiological, biochemical and immunological responses. Thus, the estimated global increase of these contaminants in the marine environment could affect the health of these benthic organisms, with consequences at population and ecosystem levels.publishe

Assessing combined effects of long-term exposure to copper and marine heatwaves on the reef-forming serpulid Ficopomatus enigmaticus through a biomarker approach

Sessile benthic organisms can be affected by global changes and local pressures, such as metal pollution, that can lead to damages at different levels of biological organization. Effects of exposure to marine heatwaves (MHWs) alone and in combination with environmentally relevant concentration of copper (Cu) were evaluated in the reef-forming tubeworm Ficopomatus enigmaticus using a multi-biomarker approach. Biomarkers of cell membrane damage, enzymatic antioxidant defences, metabolic activity, neurotoxicity, and DNA integrity were analyzed. The exposure to Cu alone did not produce any significant effect. Exposure to MHWs alone produced effects only on metabolic activity (increase of glutathione S-transferase) and energy reserves (decrease in protein content). MHWs in combination with copper was the condition that most influenced the status of cell homeostasis of exposed F. enigmaticus. The combination of MHWs plus Cu exposure induced increase of protein carbonylation and glutathione S-transferase activity, decrease in protein/carbohydrate content and carboxylesterase activity. This study on a reef-forming organism highlighted the additive effect of a climate change-related stressor to metals pollution of marine and brackish waters

Can temperature rise change the impacts induced by e-waste on adults and sperm of Mytilus galloprovincialis?

: Nowadays, it is of utmost importance to consider climate change factors, such as ocean warming, since the risk of negative impacts derived from increased surface water temperature is predicted to be high to the biodiversity. The need for renewable energy technologies, to reduce greenhouse gas emissions, has led to the increasing use of rare earth elements (REEs). Dysprosium (Dy) is widely used in magnets, motors, electrical vehicles, and nuclear reactors, being considered a critical REE to technology due to its economic importance and high supply risk. However, the increasing use of this element contributes to the enrichment of anthropogenic REEs in aquatic systems. Nevertheless, the information on the potential toxicity of Dy is limited. Moreover, the effects of pollutants can be amplified when combined with climate change factors. Thus, this study aimed to assess the effects of Dy (10 μg/L) in the species Mytilus galloprovincialis under actual (17 °C) and predicted warming conditions (21 °C). The Dy concentration in contaminated mussels was similar between temperatures, probably due to the detoxification capacity in individuals under these treatments. The combined stressors affected the redox balance, but higher impacts were caused by Dy and warming acting alone. In terms of cellular damage, although Dy acting alone was prejudicial to mussels, warming and both stressors acting together induced higher levels of LPO and PC. The histopathological effects of Dy in the digestive tubules were independent of the temperature tested. Regarding effects on sperm, only warming induced cellular damage, while both stressors, alone and together, impaired sperm movement. Overall, this study highlights that warming might influence the effects induced by Dy, but greater impacts were caused by the element. Eventually, the tested stressors may have consequences on mussels' reproduction capacity as well as their growth, abundance, and survival

Comparative subcellular responses to pharmaceutical exposures in the mussel Mytilus galloprovincialis: An in vitro study

Pharmaceutical active compounds (PhACs) have raised concerns in the last decade due to their increased consumption and inadequate elimination during discharge, resulting in their introduction into water systems and potential significant threats to non-target organisms. However, few studies have investigated the sublethal impacts of PhAC exposure on marine invertebrates. Thus, the present study aimed to assess tissue-specific responses in Mytilus galloprovincialis to sodium lauryl sulfate (SLS), salicylic acid (SA), and caffeine (CAF) (4.0 mg/L, 4.0 mg/L and 2.0 μg/L, respectively). Short-term in vitro exposures with mussel digestive gland and gill tissues were conducted and biochemical responses related to antioxidant and detoxification capacity, cellular damage and neurotoxicity were assessed. The present results clearly showed significant differences in tissue sensitivity and biochemical responses to the contaminants tested. This study highlights the suitability of filter-feeder species as valuable model organisms for studying the sublethal effects of unintended environmental exposures to PhACs