Agata Witczak

Dr. Agata Witczak

West Pomeranian University of Technology Szczecin Poland
orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 August 2024 in Toxics
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Journal Article
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AWAgata Witczak
Agata Witczak
LPLaura Przedpełska
Laura Przedpełska
KPKamila Pokorska-Niewiada
Kamila Pokorska-Niewiada
JCJacek Cybulski
Jacek Cybulski
The threat posed by microplastics has become one of the world’s most serious problems. Recent reports indicate that the presence of microplastics has been documented not only in coastal areas and beaches, but also in water reservoirs, from which they enter the bodies of aquatic animals and humans. Microplastics can also bioaccumulate contaminants that lead to serious damage to aquatic ecosystems. The lack of comprehensive data makes it challenging to ascertain the potential consequences of acute and chronic exposure, particularly for future generations. It is crucial to acknowledge that there is still a substantial need for rapid and effective techniques to identify microplastic particles for precise evaluation. Additionally, implementing legal regulations, limiting plastic production, and developing biodegradation methods are promising solutions, the implementation of which could limit the spread of toxic microplastics.

14 January 2021 in Nutrients
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AWAgata Witczak
Agata Witczak
APAnna Pohoryło
Anna Pohoryło
Hassan Abdel-GawadHassan Abdel-Gawad
Hassan Abdel-Gawad
The aim of the present study was to assess infant safety associated with the occurrence of endocrine-disrupting organochlorine pesticides (OCP) in breast milk. Moreover, the association between pregnant mothers’ dietary habits and these compounds levels in breast milk was investigated. Breast milk was collected at various stages of lactation. The samples were analyzed by the GC-MS method. The OCP concentrations ranged from < limit of detection (LOD) to 6.81 ng/g lipids. The highest OCP concentrations in breast milk occurred primarily within the first month of lactation, and decreased over the lactation period. It was found that the maternal consumption of certain food products—in particular pork, beef, poultry, eggs, and dairy products—could have affected the content of 1,1’-(2,2,2-Trichloroethane-1,1-diyl)bis(4-chlorobenzene), called DDT and its metabolites in the breast milk. The levels of beta-endosulfan were positively correlated with fish and poultry consumption. The redundancy analysis indicated that the diets of the pregnant women had an important impact on pesticide residues in the breast milk. There is a potential possibility of lowering the content of organochlorine compounds in breast milk by adhering to nutritional recommendations, e.g., avoiding the excessive consumption of fish and other raw food materials of unknown origin.

13 October 2014 in Journal of Environmental Science and Health, Part B
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AWAgata Witczak
Agata Witczak
Hassan Abdel-GawadHassan Abdel-Gawad
Hassan Abdel-Gawad
Currently, butter and margarine are food products attracting wide customer interest. Every day, consumers around the world buy these products for human consumption. Butter is obtained from milk fat, while margarine is derived from vegetable oils. The content of organochlorine pesticide (OCP) residues was examined in both types of these high fatty products. A gas chromatograph with MSD (HP 5973) detector was used for the determination of pesticides such as α-HCH, β-HCH, γ-HCH, DDT, DDD, DDE, aldrin, dieldrin, endrin, heptachlor and heptachlor epoxide. The examined products had diverse concentrations of the analyzed compounds. Visible was the division based on the origin of the product, which might be composed of animal or vegetable fats. The research has revealed the presence of OCP residues in all examined spreads. Quantities of organochlorine compounds did not pose an immediate danger to the consumers’ health. Human and environmental health risk assessment was carried out by the estimation of lifetime average daily dose (LADD) and non-carcinogenic health hazard quotient (HQ). Total estimated LADD ranged between 1.3 × 10−5 and 3.1 × 10−5 mg kg−1 d−1 for butter, and 1.9 × 10−6 and 4.6 × 10−6 mg kg−1 d−1 for margarine and mix spread. The HQ ranged between 1.1 × 10−4 and 3.7 × 10−4 for butter, and 1.4 × 10−5 and 9.0 × 10−6 for margarine and mix spread for adults. These estimated HQs were within the safe acceptable limits, indicating a negligible risk to the residents of the study area.

11 April 2021 in Foods
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ASAgnieszka Strzelczak
Agnieszka Strzelczak
JBJerzy A. Balejko
Jerzy A. Balejko
Mariusz SzymczakMariusz Szymczak
Mariusz Szymczak
AWAgata Witczak
Agata Witczak
The technological properties of raw fish are influenced by the changes in protein structure under heating, which determines the texture and quality of the product. The aim of the study was to examine the protein denaturation temperature and the rheological properties of Baltic herring muscle tissue. The thermal properties were determined by the differential scanning calorimetry (DSC) method and the rheological properties were determined using dynamic oscillatory tests. DSC showed four peaks associated with denaturing transformations of myosin (39.59 °C), sarcoplasm (51.67 °C), connective tissue (63.16 °C), and actin (74.40 °C). Analysis showed that not all transformations occurred according to the same kinetic model. The first two and the last peak are described by 1st order kinetics, while peak 3 is described by 2nd order kinetics. Correlating the changes in fish tissue structure during heating with the rheological characteristics provides more information. The obtained kinetics models correlated very strongly with the results of model testing. Rheological changes of the G’ and G” values had two inflexion points and demonstrate a high degree of convergence with the DSC changes of herring muscle tissue from 20 to 85 °C.

2 September 2013 in Journal of Environmental Science and Health, Part B
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ACArtur Ciemniak
Artur Ciemniak
AWAgata Witczak
Agata Witczak
KMKamila Mocek
Kamila Mocek
The aim of this study was to assess honey contamination by polycyclic aromatic hydrocarbons. Six species of honey were examined, as well as rape blossom and soil from villages Pęczerzyno and Przybysław in West Pomerania, Poland. The instrumental analysis was performed using a HP 6890 gas chromatograph coupled to a HP 5973 mass spectrometer with selected ion monitoring (SIM). Quantification was done by gas chromatography-mass spectrometry (GC-MS) using perdeuterated internal standards. Both soil samples showed high levels of all 23 PAHs, whereas honey contained mostly non-carcinogenic PAHs of low molecular weight. The most contaminated honey from Pęczerzyno contained 0.24 μg kg-1 benzo[a]pyrene. Moreover, despite low contamination of honey, a positive correlation was found between PAH content in honey, blossom and soil.

19 March 2012 in Journal of Environmental Science and Health, Part B
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AWAgata Witczak
Agata Witczak
Hassan Abdel-GawadHassan Abdel-Gawad
Hassan Abdel-Gawad
Organic and conventional crops were studied by identifying the relationship between persistent organic pollutants in cereals, vegetables and soil. The residues of organochlorine pesticides and polychlorinated biphenyls (PCBs) were determined in grains (rye and wheat), vegetables (carrots and beets) and soil collected from the fields. PCB residues recorded in the beets from organic farming were as high as 3.71 ppb dry weight (dry wt.), while in the soil from conventional farming of beets 0.53 ppb dry wt. Among vegetables, higher concentrations of pesticides were detected in organically grown beets (190.63 ppb dry wt.). Soil samples from the organic farming contained lower levels of organochlorine pesticide residues compared to the conventional farming. Taking into account toxicity equivalent (TEQ), the conventionally grown carrots accumulated the most toxic PCBs. Non-ortho and mono-ortho PCBs were also noted in the grain of conventionally grown rye and amounted to 3.05 pg-TEQ/g wet wt.