Lucyna Falkowska's research while affiliated with University of Gdansk and other places

This study focused on evaluating the elimination of Hg by Baltic grey seals (Halichoerus grypus grypus) via faeces and pelage. In addition, we investigated the potential for ecosystem contamination via these routes. Faeces and fur were collected in 2014-2017 from captive adult grey seals and their pups. The concentrations of total mercury (THg) and methylmercury (MeHg) were measured in the samples. The amount of mercury eliminated in a labile form (the sum of the bioavailable Hg(II) and methylmercury) was also determined. An adult seal removed about 46% of mercury supplied with food via the faeces, of which only 17% was MeHg. Considering that mercury is mainly supplied to the body as MeHg, it can be assumed that mercury excreted along with faeces has undergone transformation inside the animal body. Despite the much higher THg and MeHg concentrations measured in fur, the incorporation of mercury into newly formed fur is a less effective method of Hg elimination removing just 4% of mercury entering the body via the alimentary route. The presence of mercury in lanugo is evidence of maternal transfer. First droppings of the pups were characterised by the highest content of MeHg and a low THg concentration. Then, despite the limited supply of mercury with food, and the rapid growth of the pup, the concentration of THg increased, suggesting that mercury started to be transformed into less toxic forms. It was estimated that faeces and fur expelled by seals could deliver about 800 g of mercury to the Baltic Sea. For both faeces and fur, most of the mercury (>95% for excrements and >85% for fur) was expelled in a labile form that can be quickly recycled.

Concentrations of 16 PAHs of different molecular weight and carcinogenic potency were measured in PM2.5 aerosols collected in the coastal zone of southern Baltic Sea (Gdynia, Poland) during the end of the heating and beginning of the non-heating season of 2012. Obtained results showed that coal combustion (pyrogenic source) contributed to the highest emission of PAHs during the heating season. However, similar concentrations of highly carcinogenic PAHs were detected in the non-heating period. The analysis of prevailing wind directions, air mass trajectories and diagnostic PAH ratios revealed that in addition to land transport emission (mainly from diesel vehicles), the increase in sea shipping traffic during the non-heating season contributed to the high concentrations of detected carcinogenic PAHs. We conclude that the increasing maritime activity in the southern Baltic Sea region might have an adverse effect on both environmental and human health. Therefore, it should receive more attention by the Polish government as a pollutant source.

Alimentary exposure is the main factor determining halogenated organic compound pollution of wildlife, with birds' eggs recognised as bioindicators of these contaminants and often used as a non-invasive monitoring tool. Comparisons of bird species from two aquatic environments, namely a marine coastal area (Gdansk Bay) and an inland reservoir (Włocławek Dam on the Vistula River), indicated significant differences in egg contamination. Herring gull eggs from Włocławek Dam had high concentrations of highly chlorinated dioxin (i.e. octachlorodibenzodioxin, which accounted for 37% of all polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo furans, PCDD/Fs). In contrast, eggs from terns feeding along the coastal area of the Southern Baltic contained high concentrations of lowly chlorinated furans (i.e. pentachlorodibezofuran, which accounted for 46 and 45% of all PCDD/Fs in eggs from the sandwich tern and common tern respectively). The congener patterns in terns' eggs were similar to those reported previously for Baltic fish. Polychlorinated biphenyl congener 180 had the highest concentrations among the mono-ortho chlorinated biphenyls, whereas concentrations of non-dioxin-like chlorinated biphenyls were 10-fold higher than those of the other congeners analysed, but the congener pattern in eggs from both species (sandwich and common tern) was similar to that reported in other studies. Among the hexabromocyclododecane (HBCD) isomers, α-HBCD dominated in all eggs analysed (accounting for >97% of all HBCDs). The total HBCD concentration in gulls' eggs from the inland reservoir was approximately half that in eggs from the common and sandwich terns (mean ± s.d. 47.33 ± 33.22 v. 97.98 ± 59.69 and 104.00 ± 63.66 ng g⁻¹ lipid weight respectively).

Mercury enters the body of seabirds in its most toxic organic form, i.e. methylmercury, mainly via the alimentary tract. Inside the body, mercury is transformed into less toxic forms and accumulates in the internal organs. The process of mercury removal from the body, most effective during the formation of new feathers and claws, is beneficial for the bird. The presented research was undertaken on account of the high affinity of mercury to keratin – a protein that forms feathers and claws – to compare the concentration levels (Hg TOT ) in these structures and to assess their contribution to the purification of the body of herring gulls (Larus argentatus) Bird feathers are the only epidermal structure that is extensively described in the literature, whereas the claws have so far been poorly researched. The study has shown that mercury in claws is built in as effectively as in feathers, and the obtained concentrations were within a wide range of 127.2–5341.5 ng Hg TOT g –1 of dry weight. In addition, the concentrations of total mercury accumulated in the claws were a better reflection of Hg levels in internal organs compared to feathers.

This study presents levels of ¹³⁷Cs and ⁴⁰K concentrations in the placentas of seals gathered in the period 2007–2015. The mean activity of ¹³⁷Cs and ⁴⁰K was 5.49 Bq kg⁻¹w.w. and 136.6 Bq kg⁻¹ ww respectively. Statistically significant correlation was observed between the ¹³⁷Cs activities in placenta and in herring—the staple food for seals. The concentrations of ¹³⁷Cs and ⁴⁰K were also determined in other tissues (muscle, liver, lung, and brain) of wild seals. The concentrations of ¹³⁷Cs were from 2.59 Bq⁻¹ ww (lungs) to 24.3 Bq kg⁻¹ ww (muscles). The transfer factor values for ¹³⁷Cs (seal tissue/fish) ranged from 0.89 to 2.42 in the case of the placentas and from 1.35 to 8.17 in the case of the muscle. For adults seal, the effective dose from ¹³⁷Cs was 2.98 nGy h⁻¹. The mean external radiation dose to pup was 0.77 nGy h⁻¹ from ¹³⁷Cs and 6.69 nGy h⁻¹ from ⁴⁰K.

Using the blood of grey seal pups, the blood and milk of female grey seals inhabiting the Hel Marine Station of Gdansk University's Institute of Oceanography (HMS), we monitored the transfer of total mercury (THg), methylmercury (MeHg), and selenium (Se)with blood during foetal life and nursing. Changes in the concentration of mercury and selenium were characterised in the pups' blood during their first three months of life when they transition from suckling, to a post-weaning fast, to eating fish. In the blood of pregnant females, there was a significant decrease in THg and MeHg concentrations throughout the gestation, indicating the transfer of these toxins through the placenta into the foetus. At no other stage of the pup's development was there such a high level of THg and MeHg as on the day of birth, despite the incorporation of mercury into the lanugo during foetal growth. This suggests that the maternal transfer of mercury during gestation may be the time of greatest mercury exposure for a young seal pup. The consumption of milk caused a rapid increase in weight and a lowering of the mercury level in the blood in the subsequent days of the pups' life. The postweaning fast was the period of the lowest mercury concentration. The switch to a diet consisting of fish caused a systematic increase in the concentration of mercury in the blood of the pups. Milk was the significant source of selenium for pups and the selenium concentration in females' blood was reduced during lactation. The nursing period seemed to have the greatest impact on the mercury and selenium blood levels in examined seals. Natural development of the grey seal pup created an opportunity to decrease the levels of toxic substances obtained through the maternal transfer during foetal growth.

• The aim of this work was to develop the methods of determination for phenol derivatives: bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP), in the whole body of herring Clupea harengus and in physiological fluids of the Baltic grey seal Halichoerus grypus grypus (blood and milk). • Methods were based on liquid chromatography coupled with a fluorescence detector (HPLC-FL). • These methods were satisfactorily validated, each showing good recovery (>80%) and precision (RSD < 15%). Regarding the limit of quantification (LOQ), this was established at <2 ng g⁻¹ for herring, <0.07 ng cm⁻³ for blood and <0.1 ng cm⁻³ for milk.