Scientific paper
Scientific paper
Variability in Toxicity of Plastic Leachates as a Function of Weathering and Polymer Type: A Screening Study with the Copepod Nitocra spinipes
chemicals
,
debris
,
harpacticoid copepod
,
ingestion
,
marine-environment
,
microplastics
,
persistent organic pollutants
,
polyethylene
,
transport
,
water
The production and use of plastic over many decades has resulted in its accumulation in the world's oceans. Plastic debris poses a range of potential risks to the marine environment and its biota. Especially, the potential hazards of small plastic debris and chemicals associated with plastic have not been extensively studied. When buoyant plastic is exposed to ultraviolet radiation, it will slowly degrade and leach chemicals into surrounding waters. These leachates can include additives, sorbed organic pollutants, and degradation products of the plastic polymers. While most hazard assessments have focused on studying adverse effects due to the uptake of plastic, toxicity studies of the leachates of plastics are less common. To begin to address this knowledge gap, we studied the acute toxicity of leachates from diverse plastics in the harpacticoid copepod Nitocra spinipes. Our results show that leachates caused a higher toxicity after plastic was exposed to ultraviolet light compared to leaching in darkness. We observed differences in toxicity for different polymer types: polyvinyl chloride and polypropylene resulted in the most toxic leachates, while polystyrene and poly[ethylene terephthalate] were least toxic. Furthermore, we observed increased toxicity of leachates from some plastics that had been weathered in the real marine environment compared to matching new materials. Our results indicate that both weathering condition and polymer type influence the toxicity of plastic leachates.
Scientific paper
A call for urgent action to safeguard our planet and our health in line with the helsinki declaration
air pollution
,
allergy
,
chemical pollution
,
climate change
,
diseases
,
environmental biodiversity
,
exposure
,
nature
,
planetary health
,
urbanization
In 2015, the Rockefeller Foundation-Lancet Commission launched a report introducing a novel approach called Planetary Health and proposed a concept, a strategy and a course of action. To discuss the concept of Planetary Health in the context of Europe, a conference entitled: "Europe That Protects: Safeguarding Our Planet, Safeguarding Our Health" was held in Helsinki in December 2019. The conference participants concluded with a need for action to support Planetary Health during the 2020s. The Helsinki Declaration emphasizes the urgency to act as scientific evidence shows that human activities are causing climate change, biodiversity loss, land degradation, overuse of natural resources and pollution. They threaten the health and safety of human kind. Global, regional, national, local and individual initiatives are called for and multidisciplinary and multiT-sectorial actions and measures are needed. A framework for an action plan is suggested that can be modified for local needs. Accordingly, a shift from fragmented approaches to policy and practice towards systematic actions will promote human health and health of the planet. Systems thinking will feed into conserving nature and biodiversity, and into halting climate change. The Planetary Health paradigm - the health of human civilization and the state of natural systems on which it depends -must become the driver for all policies.
Scientific paper
Mechanistic Investigation of Dimethylmercury Formation Mediated by a Sulfide Mineral Surface
cycle
,
elastic band method
,
elemental mercury
,
generalized gradient approximation
,
methylmercury
,
molecules
,
ocean
,
paths
,
water
Mercury (Hg) pollution is a global environmental problem. The abiotic formation of dimethylmercury (DMeHg) from monomethylmercury (MMeHg) may account for a large portion of DMeHg in oceans. Previous experimental work has shown that abiotic formation of DMeHg from MMeHg can be facilitated by reduced sulfur groups on sulfide mineral surfaces. In that work, a mechanism was proposed in which neighboring MMeHg moieties bound to sulfide sites on a mineral surface react through an S(N)2-type mechanism to form DMeHg and incorporate the remaining Hg atoms into the mineral surface. Here, we perform density functional theory calculations to explore the mechanisms of DMeHg formation on the 110 surface of a CdS(s) (hawleyite) nanoparticle. We show that coordination of MMeHg substituents to adjacent reduced sulfur groups protruding from the surface indeed facilitates DMeHg formation and that the reaction proceeds through direct transmethylation from one MMeHg substituent to another. Coordination of Hg by multiple S atoms provides a transition-state stabilization and activates a C-Hg bond for methyl transfer. In addition, solvation effects play an important role in the surface reconstruction of the nanoparticle and in decreasing the energetic barrier for DMeHg formation relative to the corresponding reaction in vacuo.
Scientific paper
Persistent organic pollutants (POPs) in fish species from different lakes of the lesser Himalayan region (LHR), Pakistan: The influence of proximal sources in distribution of POPs
bioaccumulation
,
brominated flame retardants
,
dechloran plus dp
,
dietary proxies (delta n-15 and delta c-13)
,
dioxin-like pcbs
,
feeding regimes
,
fresh-water fish
,
kohonen self-organizing maps
,
long range transport
,
organochlorine pesticides ocps
,
polybrominated diphenyl ethers
,
polychlorinated-biphenyls pcbs
,
polycyclic aromatic hydrocarbons
,
tibetan plateau
,
toxic equivalency factors
,
trophic position
Fish dwelling in remote mountain water systems are sensitive to long term exposure of POPs and can be used as an important bioindicator of POPs pollution in fragile mountain ecosystems. Current study aimed to investigate the concentrations and patterns of organic pollutants in fish tissues from different lakes of the Lesser Himalayan Region (LHR). OCPs, PCBs, PBDEs were analyzed in four common edible fish species of the LHR: Oncorhynchus mykiss, Labeo rohita, Hypophthalmichthys molitrix and Orechromis aureus. The fish were collected from lakes with different types of catchment areas (glacial, non-glacial mountain region and urban region) and extent of anthropogenic influence. The levels OCPs, PCBs and PBDEs analyzed in the selected fish species were in range of 0.21-587, 6.4-138 and 1.2-14 ng g(-1) lw, respectively. The SDDTs, higher chlorinated PCBs, tetra- and pentaBDEs were more prevalent in urban and remote lakes whereas pp'-DDE, lower chlorinated PCBs and BDE-47 and -99 were predominant in fish species from glacial lakes. SDDTs, SPCBs and SPBDEs showed statistically significant differences (p < 0.05) among species, trophic guilds (carnivore, herbivore and omnivore) and feeding regimes (surface, bottom and column feeder) and SHCH showed a significant difference only among trophic guilds. The stable isotope values of delta N-15 and delta C-13 differed significantly among species for SSHCH, SPCBs, SPBDEs (p < 0.05) and SDDT (p < 0.01). The range of delta C-13 values (-34 to-19%) indicated the importance of littoral and pelagic sources of dietary carbon. Trophic position and dietary proxieswere identified as important variables for explaining the variability of the studied compounds. Kohonen self-organizing maps (SOM) showed that in addition to trophic position and other physiological characteristics of fish, that the type of lakes and proximal sources of POPswere the most important predictors for distribution of organic contaminants in fish samples from LHR. (C)2020 Elsevier B.V. All rights reserved.
Scientific paper
Non-target screening for characterization of chemicals in human ovarian follicular fluid
Scientific paper
Organophosphate Esters in the Canadian Arctic Ocean
air
,
contaminants
,
flame retardants
,
pacific
,
particles
,
plasticizers
,
water
Eleven organophosphate esters (OPEs) were detected in surface water and sediment samples from yearly sampling (2013-2018) in the Canadian Arctic. In water samples, Sigma chlorinated-OPEs (Cl-OPEs) concentrations exceeded Sigma non-chlorinated-OPEs (non-Cl-OPEs) with median concentrations of 10 ng L-1 and 1.3 ng L-1, respectively. In sediment samples, Sigma Cl-OPEs and Sigma nonchlorinated-OPEs had median concentrations of 4.5 and 2.5 ng g(-1), respectively. High concentrations of OPEs in samples from the Mackenzie River plume suggest riverine discharge as an OPE source to the Canadian Arctic. The prevalence of OPEs at other sites is consistent with long-range transport. The OPE inventory of the Canadian Arctic Ocean representative of years 2013-2018 was estimated at 450-16,000 tonnes with a median Sigma 11OPE mass of 4100 tonnes with >99% of the OPE inventory estimated to be in the water column. These results highlight the importance of OPEs as water-based Arctic contaminants subject to long-range transport and local sources. The high OPE inventory in the water column of the Canadian Arctic Ocean points to the need for international regulatory mechanisms for persistent and mobile organic contaminants (PMOCs) that are not covered by the risk assessment criteria of the Stockholm Convention.
Scientific paper
Introducing the HERA Core Agenda for the European Environment, Climate & Health Research
Scientific paper
Defining the Scope of Exposome Studies and Research Needs from a Multidisciplinary Perspective
air pollution
,
cancer
,
dietary
,
disease
,
environment
,
exposure
,
high-resolution metabolomics
,
ion mobility spectrometry
,
mass spectrometry
,
mortality
The concept of the exposome was introduced over 15 years ago to reflect the important role that the environment exerts on health and disease. While originally viewed as a call-to-arms to develop more comprehensive exposure assessment methods applicable at the individual level and throughout the life course, the scope of the exposome has now expanded to include the associated biological response. In order to explore these concepts, a workshop was hosted by the Gunma University Initiative for Advanced Research (GIAR, Japan) to discuss the scope of exposomics from an international and multidisciplinary perspective. This Global Perspective is a summary of the discussions with emphasis on (1) top-down, bottom-up, and functional approaches to exposomics, (2) the need for integration and standardization of LC- and GC-based high-resolution mass spectrometry methods for untargeted exposome analyses, (3) the design of an exposomics study, (4) the requirement for open science workflows including mass spectral libraries and public databases, (5) the necessity for large investments in mass spectrometry infrastructure in order to sequence the exposome, and (6) the role of the exposome in precision medicine and nutrition to create personalized environmental exposure profiles. Recommendations are made on key issues to encourage continued advancement and cooperation in exposomics.
Scientific paper
Degradation of naturally produced hydroxylated polybrominated diphenyl ethers in Baltic Sea sediment via reductive debromination
algae
,
biodegradation
,
oh-pbde
,
pbde
,
reduction
,
sediment
Over the last two decades, the occurrence of hydroxylated polybrominated diphenyl ethers (OH-PBDEs) has been observed to be nearly ubiquitous among Baltic Sea filamentous macroalgae. High concentrations are continuously recorded among red, green, and brown filamentous algae. Several of these algae species are ephemeral, and when large parts of the colonies decay at the end of their lifecycles, the OH-PBDEs are expected to largely partition to the sediment. In this study, the fate of OH-PBDEs in Baltic Sea sediment was investigated, with focus on the effect of reductive debromination. During chemical debromination, it was observed that the half-life could differ with as much as two orders of magnitude between a pentabrominated and a tetrabrominated congener. Using collected Baltic Sea sediment, it was further observed that the half-life of spiked pentabrominated OH-PBDEs spanned from a few days up to a few weeks in room temperature. At 4 degrees C, it took 6 months to achieve a 50% decrease in concentration of the fasted degrading congener. Clear differences in selectivity between chemical debromination and debromination in sediment were also observed when studying the major reaction products. Baltic Sea sediment seems to have a good capacity for reducing naturally produced OH-PBDEs.
Scientific paper
Photolytically induced changes in composition and volatility of biogenic secondary organic aerosol from nitrate radical oxidation during night-to-day transition
alpha-pinene
,
carbonyl nitrates
,
chemical composition
,
evaporation kinetics
,
isoprene oxidation
,
mass-spectrometer
,
model
,
no3
,
optical-properties
,
photolysis
Night-time reactions of biogenic volatile organic compounds (BVOCs) and nitrate radicals (NO3) can lead to the formation of NO3-initiated biogenic secondary organic aerosol (BSOANO(3)). Here, we study the impacts of light exposure on the chemical composition and volatility of BSOANO(3) formed in the dark from three precursors (isoprene, alpha-pinene, and beta-caryophyllene) in atmospheric simulation chamber experiments. Our study represents BSOANO(3) formation conditions where reactions between peroxy radicals (RO2 + RO2) and between RO2 and NO3 are favoured. The emphasis here is on the identification of particle-phase organonitrates (ONs) formed in the dark and their changes during photolytic ageing on timescales of similar to 1 h. The chemical composition of particle-phase compounds was measured with a chemical ionization mass spectrometer with a filter inlet for gases and aerosols (FIGAERO-CIMS) and an extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF). Volatility information on BSOANO(3) was derived from FIGAERO-CIMS desorption profiles (thermograms) and a volatility tandem differential mobility analyser (VTDMA). During photolytic ageing, there was a relatively small change in mass due to evaporation (< 5 % for the isoprene and alpha-pinene BSOANO3, and 12 % for the beta-caryophyllene BSOANO(3)), but we observed significant changes in the chemical composition of the BSOANO(3). Overall, 48 %, 44 %, and 60 % of the respective total signal for the isoprene, alpha-pinene, and beta-caryophyllene BSOANO(3) was sensitive to photolytic ageing and exhibited decay. The photolabile compounds include both monomers and oligomers. Oligomers can decompose into their monomer units through photolysis of the bonds (e.g. likely O-O) between them. Fragmentation of both oligomers and monomers also happened at other positions, causing the formation of compounds with shorter carbon skeletons. The cleavage of the nitrate functional group from the carbon chain was likely not a main degradation pathway in our experiments. In addition, photolytic degradation of compounds changes their volatility and can lead to evaporation. We use different methods to assess bulk volatilities and discuss their changes during both dark ageing and photolysis in the context of the chemical changes that we observed. We also reveal large uncertainties in saturation vapour pressure estimated from parameterizations for the ON oligomers with multiple nitrate groups. Overall, our results suggest that photolysis causes photodegradation of a substantial fraction of BSOANO(3), changes both the chemical composition and the bulk volatility of the particles, and might be a potentially important loss pathway of BSOANO(3) during the night-to-day transition.
