Pollution characteristics and risk assessment of dioxins and arsenic species in agricultural and marine products

Abstract

Arsenic (As) is a widely occurring contaminant that is released both naturally and as a result of anthropogenic activity. It is a metalloid that exists in various inorganic and organic forms. The inorganic forms of arsenic are more toxic compared to the organic forms. Polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs) are part of a group of persistent, lipophilic, bioaccumulative, and ubiquitous compounds that are among the most toxic chemicals to environmental and human health. Dioxins are typically formed during incomplete combustion processes in the presence of chlorine. This can occur from both natural sources, such as volcanic eruptions and forest fires, as well as anthropogenic activities, such as metal industry production, chemical production, and waste incineration. In contrast, PCBs are manmade compounds that are primarily used in plasticizers and non-flammable oils in transformers, dielectrical fluids, paints and printing inks, capacitors, and many other industrial applications. PCBs are suitable for these products due to their low flammability and high chemical stability. Although PCB use and production has been banned in most developed countries since the 1970s, these compounds are still one of the most widespread environmental contamination, and they are present to some extent in all food products. The main sources of global human exposure to these chemicals include grain-based, processed food products such as water, rice, and wheat bread. Other food items that are major contributors to dietary exposure to inorganic As in the general Korean population include food for rice grains, rice-based products, water, beer, coffee, fish, agricultural products, and special dietary uses. The major adverse effects that are associated with the long-term ingestion of inorganic As in humans include the following: cancer, neurotoxicity, skin lesions, diabetes, cardiovascular diseases, and developmental toxicity. There is also new evidence that it has negative effects on fetal and infant development, particularly reduced birth weight. People who have high rice intake in Europe and high consumers of algae-based products can often exceed their tolerable weekly intake of inorganic As. The available evidence does not indicate any difference in dietary exposure for vegetarians compared to the general population, unless they consume a large amount of algae-based food products. Due to problems with the analysis of metals including As in a number of food products, maximum levels of As were initially only determined for rice and other cereal-based products. With the availability of reliable analysis methods, an As monitoring project was organized for the period 2013−2017. The objective of this monitoring project was to generate reliable occurrence data that could be used to accurately evaluate the need for determining additional maximum As levels for other food products. The products covered in this monitoring project included cereal grains, cereal-based products, drinking water, beer, milk, dairy products, fish and seafood (including hijiki), fruits, vegetables, and food supplements. Secondly, PCDD/F and dioxin-like (dl) PCB concentrations were measured by analyzing various foods consumed in Korea. While previous studies focused on monitoring specific food groups (e.g., fish, crustaceans, mollusks, etc.) or had a small sample size, this study selected very large-scale food groups that represented the dietary habits of a large population. The results were compared with the Tolerable Daily Intake (TDI) for risk assessment. Based on the analysis of fishery and agricultural products, the combined exposure to dioxins through these foods was 11.93% based on the TDI, and the highest contribution was from fishery products. An assessment for a 95% extreme intake group and different age groups was also performed, and there were no results exceeding the TDI. An excess rate was determined based on the respondents' dietary habits. Based on the results, health metrics such as neurotoxicity, monthly consumption limit, and cancer death rate were calculated. Although toxic compounds such as dl-PCBs and PCDD/Fs are detected in high concentrations in food from some countries and have attracted considerable attention in public health, the contamination statuses of these compounds are unclear among the general population in Korea. The Korea Food & Drug Administration has been coordinating monitoring programs for marker (or indicator) PCBs, dioxin-like PCBs, and PCDD/Fs since 2012. The purpose of this study was to measure the contamination levels and investigate the residue profiles of PCDD/Fs and dl-PCBs in agricultural and marine products collected from general markets in Korea. Lastly, various aspects of human exposure to contaminants from various foods were considered. In addition to average intake, extreme intake, each age group, the effects of different cooking methods, nutritional ingredients, and potential health risks were comprehensively taken into account. The information obtained can help improve consumer awareness and help policymakers implement strategies for risk management for contaminants in the environment.