A four-year survey in the farming region of Chile, occurrence and human exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans, and dioxin -like polychlorinated biphenyls in different raw meats

Highlights

• Dioxins were monitored in the farming area of Chile

• Penta and tetra chlorinated congeners dominated PCDD/Fs profile while PCB 126 dominated the dl-PCBs profiles

• Residue concentrations were lower or in the same range compared with international levels and under the maximum limits (EC, 2011).

• Levels reported were in the safety margin for human exposure and are the first published for the South American region

Abstract

For the first time in South America, a four-year survey (2011–2014) was conducted to assess the occurrence of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in different raw meats (bovine, pork, ovine, chicken, and turkey) sampled from ten of the fifteen regions of Chile. When expressed as pg World Health Organization Toxic Equivalent (WHO-TEQ₂₀₀₅) g⁻¹ fat, the highest PCDD/F values for each species were 0.54 (bovine-2012), 0.27 (pork-2013), 0.23 (ovine-2011), 0.61 (chickens-2013), and 0.34 (turkey-2012). The highest mean dl-PCBs levels were 0.18 (bovine-2011), 0.05 (pork-2014), 0.13 (ovine-2011), 0.1 (chicken-2014), and 0.21 (turkey-2013). Penta- and tetra-chlorinated congeners dominated PCDD/F WHO-TEQ₂₀₀₅ profiles during the survey, while PCB 126 dominated dl-PCBs profiles. Statistically significant interspecies differences were found. Dietary intake was also estimated, and the highest total PCDD/F and dl-PCBs values, found in poultry meat, were 0.09 pg WHO-TEQ₂₀₀₅ kg⁻¹ bw d⁻¹ (2013) for adults and 0.36 pg WHO-TEQ₂₀₀₅ kg⁻¹ bw d^− 1 (2013) for children. The concentrations and dietary intakes for the studied compounds in raw meat were below international and national maximum permitted limits.

Introduction

Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) negatively affect human health (WHO, 1998, Hernández et al., 2015a, Hernández et al., 2015b, Boada et al., 2016). These compounds are primarily released into the environment unintentionally by heavy industry and incineration plants during incomplete combustion (Olie et al., 1977, Fiedler et al., 2000, Caserini et al., 2004, Colombo et al., 2011, Liu et al., 2015) and as a byproduct of organochlorine chemical production (COM, 2001, Hoogenboom, 2012). Furthermore, dl-PCBs are commonly used in many industrial applications, most notably as insulating and cooling fluids for industrial transformers and capacitors (UNEP, 2001, EFSA and European Food Safety Authority, 2010). Consequently, PCDD/Fs and dl-PCBs are now ubiquitously present in the environment, a situation that has resulted in concerns regarding the environmental persistence, bioaccumulation potential, and toxicity (Malisch and Kotz, 2014, Hoogenboom et al., 2015). Health impacts associated with these compounds include immunotoxicity, carcinogenicity, and detrimental developmental and reproductive effects (IARC, 1997, WHO, 2010, Hernández et al., 2015a, Hernández et al., 2015b, Boada et al., 2016).

In terms of food safety, public health efforts focus on evaluating the presence of and preventing contamination from these xenobiotics in animal-origin products. Policies and regulations exist to decrease the emission of these pollutants into the environment and to preclude high levels in feed and food (Hoogenboom et al., 2015). Notably, the European Commission (EC) has approved important measures for regulating PCDD/Fs and dl-PCBs levels in food and feed, with the latest EC regulations regarding levels of these persistent organic pollutants published in 2011 for food and 2012 for feed (EC, 2011, EC, 2012). Furthermore, several research groups have assessed the levels of these compounds in products of animal origin (Abad et al., 2002, Focant et al., 2002, Kiviranta et al., 2004Loutfy et al., 2006;Loutfy et al., 2007, Huwe et al., 2009, Marin et al., 2011, Zhang et al., 2013, Pizarro-Aránguiz et al., 2015, Zhang et al., 2015, Pemberthy et al., 2016) and have reported major contamination incidents of feed and food (Malisch, 2000, Llerena et al., 2001, Hoogenboom and Traag., 2003, Hoogenboom. et al., 2006, Ábalos et al., 2008, Traag. et al., 2009, Kim et al., 2011, Marnane, 2012).

Chile, located along the southwestern coast of South America, presents unique geographic characteristics, with the arid Atacama Desert in the north, the Andes Mountain Range in the east, the Pacific Ocean in the west, and the sub-Antarctic Magallanes Region in the south. These natural boundaries insulate Chile from various biological risks, such as aphthous fever, among others. However, these geographical features do not protect against environmental pollution, the sources of which are usually local in terms of food production. In 2008, for example, pork production suffered an environmental incident that originated from contaminated food additives (Kim et al., 2011). This event led Chile to implement national monitoring program for contaminants in animal-origin products for human consumption (MINSAL, 2009). Despite this effort, high PCDD/F levels were found in 2013 in exported chicken meat (SAG, 2013).

In Chile, animal farming is concentrated in valleys between the centrally located Metropolitan and Los Rios Regions (32–41°S), an area that also contains the most populated cities. Animal farms that attend to local needs can also be found near the principal cities of nearly each province in the country (Pizarro-Aránguiz et al., 2015). Conditions of the central valley region promote environmental pollution, with studies citing both natural and anthropogenic sources. Specifically, more than half the total inhabitants of Chile reside in the central valley region, resulting in concentrated vehicle emissions, as well as emissions from different industrial sources (e.g. refineries, mining, cement kilns, paper production, and energy generation). Furthermore, uncontrollable summer forest fires in the northern area and active volcanos in the southern area of the central valley region represent natural factors for pollution (Pozo et al., 2004, Pizarro-Aránguiz et al., 2015).

Despite this existing knowledge, there is a lack of national scientific data related to the levels and congener profiles of these xenobiotics in food for human consumption, with the exception of dairy products (Pizarro-Aránguiz et al., 2015). Therefore, the aims of this study were to assess and report on PCDD/F levels, dl-PCBs levels, and congener profiles, as well as to estimate human exposure to these pollutants in different raw meat products for human consumption obtained via an established monitoring program across several Chilean regions between 2011 and 2014.