Per- and polyfluoroalkyl substances (PFAS), trace elements and life history parameters of mass-stranded common dolphins (Delphinus delphis) in New Zealand.

Profiles of 33 PFAS analytes and 12 essential and non-essential trace elements were measured in livers of stranded common dolphins (Delphinus delphis) from New Zealand. PFAS concentrations reported were largely comparable to those measured in other marine mammal species globally and composed mostly of long-chain compounds including perfluorooctanesulfonic acid (PFOS), perfluorododecanoic acid (PFDoDA), perfluorotridecanoic acid (PFTrDA) and perfluorooctanesulfonamide (FOSA). PFAS profiles did not vary significantly by location, body condition, or life history. Notably, significant positive correlations were observed within respective PFAS and trace elements. However, only negative correlations were evident between these two contaminant types, suggesting different exposure and metabolic pathways. Age-associated concentrations were found for PFTrDA and four trace elements, i.e. silver, mercury, cadmium, selenium, indicating differences in the bioaccumulation biomagnification mechanisms. Overall, our results contribute to global understanding of accumulation of PFAS by offering first insights of PFAS exposure in cetaceans living within South Pacific Australasian waters.

Uptake of SigmaDDT, arsenic, cadmium, copper, and lead by lettuce and radish grown in contaminated horticultural soils.

Horticultural soils can contain elevated concentrations of selected trace elements and organochlorine pesticides as a result of long-term use of agrichemicals and soil amendments. A glasshouse study was undertaken to assess the uptake of weathered SigmaDDT {sum of the p, p'- and o, p-isomers of DDT [1,1,1-trichloro-2,2- bis( p-chlorophenyl)ethane], DDE [1,1-dichloro-2,2- bis( p-chlorophenyl)ethylene] and DDD[1,1-dichloro-2,2- bis( p-chlorophenyl)ethane]}, arsenic (As), cadmium (Cd), copper (Cu), and lead (Pb) residues by lettuce ( Lactuca sativa) and radish ( Raphanus sativus) from field-aged New Zealand horticultural soils. Concentrations of SigmaDDT, DDT, DDE, Cd, Cu, and Pb in lettuce increased with increasing soil concentrations. In radish, similar relationships were observed for SigmaDDT, DDE, and Cu. The bioaccumulation factors were less than 1 with the exception of Cd and decreased with increasing soil concentrations. Lettuce Cd concentrations for plants grown on four out of 10 assayed soils were equivalent to or exceeded the New Zealand food standard for leafy vegetables of 0.1 mg kg (-1) fresh weight. Concentrations of As, Pb, and SigmaDDT did not exceed available food standards. Overall, these results demonstrate that aged residues of SigmaDDT, As, Cd, Cu, and Pb in horticultural soils have remained phytoavailable. To be protective of human health, site-specific risk assessments and soil guideline derivations for residential settings with vegetable gardens need to consider the produce consumption pathway.

A survey of endocrine disrupting chemicals (EDCs) in municipal sewage and animal waste effluents in the Waikato region of New Zealand.

We report the results of a recent survey of the concentration of natural estrogens (17beta-estradiol, 17alpha-estradiol, estrone, estriol) and the synthetic estrogen, 17alpha-ethynylestradiol in representative animal wastes and sewage treatment plant (STP) effluents in the Waikato region of New Zealand. Dairy farm effluent samples showed high levels of estradiol (19-1360 ng/L) and its breakdown product estrone (41-3123 ng/L) compared with piggery or goat farm effluents. The combined load for these estrogens (excluding beta epimer) varied from 60 to >4000 ng/L. The piggery effluent provided the lowest total estrogen load (46 ng/L), with estrone accounting for nearly 60% of the measured estrogens in this sample. The synthetic analogue, 17alpha-ethynylestradiol was detected only in one wastewater treatment plant sample, albeit at trace level. An estrogen receptor competitive binding assay was used to test the biological activity of the samples and confirmed that most agricultural waste samples contain high levels of estrogenic compounds. The potential of these wastes to cause endocrine disruption in the receiving ecosystem is unknown at present.

Partitioning, extractability, and formation of nonextractable PAH residues in soil. 1. Compound differences in aging and sequestration.

This study was carried out to assess the influence of physicochemical properties on PAH sequestration in sterile sewage sludge-amended arable soil. Radiolabeled phenanthrene (14C-9-Phe), pyrene (14C-4,5,9,10-Pyr), and benzo[a]pyrene (14C-7-B[a]P) were spiked and aged for up to 525 days in sterile soil microcosms. The degree of compound sequestration at various sampling times was determined by their extractability with organic solvents and release from soil residues by base saponification extraction. The amount of PAH extractable by butanol and dichloromethane decreased with compound aging in the soil. The decrease in PAH extractability with aging, and the formation of nonextractable bound residues, increased with compound molecular weight, KOW and KOC. The amount of total extractable PAH determined by sequential dichloromethane soxtec and methanolic saponification extraction decreased from 98%, 97%, and 94% at day 10 to 95%, 91%, and 77%, respectively for 14C-9-Phe, 14C-4,5,9,10-Pyr, and 14C-7-B[a]P after 525 days aging. During the same aging period there was an increase in the amount of PAH released from the soil by base saponification extraction, suggesting a progressive diffusion of PAHs into hydrolyzable and recalcitrant organic matter and mineral phases of soil. Calculated half-lives for the apparent loss of PAHs by sequestration in this experiment were dependent on the method used to extract them from soil. These half-lives ranged from 96 to 1,789 days depending on the compound, and are in agreement with values obtained from previous spiking experiments using nonsterile soils. These results suggest that a considerable fraction of PAHs assumed degraded in previous studies may have been sequestered within the organic carbon and, to a lesser extent, mineral phases of soil.

Partitioning, extractability, and formation of nonextractable PAH residues in soil. 2. Effects on compound dissolution behavior.

This study was carried out to assess the influence of PAH sequestration in sterile sewage sludge-amended arable soil on their dissolution behavior. Radiolabeled phenanthrene (14C-9-Phe), pyrene (14C-4,5,9,10-Pyr), and benzo[a]pyrene (14C-7-B[a]P) were spiked and aged for up to 525 days in sterile soil microcosms. The dissolution behavior of the compounds was determined at various times using an in-situ XAD-2 sorbent method. The XAD procedure allowed the detection of hydrophobic PAHs released from the soil and demonstrated that a fraction of PAH was resistant to dissolution. The experimental data generated was analyzed using an empirical two-site model, and fitted values were obtained for the magnitude of the rapidly released compound fraction and the rate of release for the rapid and slowly released compound fractions. Increasing sequestration did not reduce the size of the rapidly released compound fraction in this soil. We did, however, observe a decrease in the rate of the fast released fraction of 14C-7-B[a]P which formed a significantly larger sequestered fraction. The duration of the dissolution experiments proved insufficientto obtain precise estimations for the rate of slow compound release from the soil, and we were unable to determine whether sequestration affected the rate of release for the slowly released compound fraction. These results demonstrate the necessity of conducting desorption experiments for a period of months if complete data on the long-term release of desorption resistant compound fractions is to be obtained.

Experimental approaches and analytical techniques for determining organic compound bound residues in soil and sediment.

Research has shown that many chemicals form persistent and permanently bound residues in soils and sediments that play an important role in soil and sediment detoxification processes, long-term compound partitioning behaviour and compound bioavailability and toxicity in soil and sediment. This article reviews the methodological approaches that have been applied to determine the nature of bound residues in soil and sediment, the application of specific analytical techniques, the type of information they generate, and their relative advantages and disadvantages. It begins by defining bound residues and discussing soil-compound interactions. The application of model compound studies for elucidating specific binding interactions is reviewed along with long-term laboratory and field soil incubation experiments. The use of radiolabelled compounds, isotopically labelled compounds and combinations of both in these experiments are outlined by examples from the literature, along with sequential extraction schemes for releasing bound residues from soil, sediment and humic materials. The importance of spectroscopic methods, and particularly nuclear magnetic resonance techniques for characterising the structure of bound residues in soil and sedimentary humic substances is discussed and illustrated by examples from the literature on the subject. The process of bound residue formation is highly complex and requires further research to establish the mechanisms of bound residue formation and their subsequent environmental and toxicological fate. Much of the uncertainty regarding the elucidation of bound residue formation arises from our poor understanding of the structure of soil and sedimentary organic matter. Significant advances in our understanding of the formation and fate of bound residues will be made when we develop a deeper insight into the complex and heterogeneous structure of soil and sedimentary organic matter.