Nitarsone, Inorganic Arsenic, and Other Arsenic Species in Turkey Meat: Exposure and Risk Assessment Based on a 2014 U.S. Market Basket Sample

Assessing the difference in contamination of retail meat with multidrug-resistant bacteria using for-consumer package label claims that indicate on-farm antibiotic use practices- United States, 2016-2019

BACKGROUND

Antibiotic use in food-producing animals can select for antibiotic resistance in bacteria that can be transmitted to people through contamination of food products during meat processing. Contamination resulting in foodborne illness contributes to adverse health outcomes. Some livestock producers have implemented antibiotic use reduction strategies marketed to consumers on regulated retail meat packaging labels ("label claims").

OBJECTIVE

We investigated whether retail meat label claims were associated with isolation of multidrug-resistant organisms (MDROs, resistant to ≥3 classes of antibiotics) from U.S. meat samples.

METHODS

We utilized retail meat data from the U.S. Food and Drug Administration National Antimicrobial Resistance Monitoring System (NARMS) collected during 2016-2019 for bacterial contamination of chicken breast, ground turkey, ground beef, and pork chops. We used modified Poisson regression models to compare the prevalence of MDRO contamination among meat samples with any antibiotic restriction label claims versus those without such claims (i.e., conventionally produced).

RESULTS

In NARMS, 62,338 meat samples were evaluated for bacterial growth from 2016-2019. Of these, 24,446 (39%) samples had label claims that indicated antibiotic use was restricted during animal production. MDROs were isolated from 2252 (4%) meat samples, of which 71% (n = 1591) were conventionally produced, and 29% (n = 661) had antibiotic restriction label claims. Compared with conventional samples, meat with antibiotic restriction label claims had a statistically lower prevalence of MDROs (adjusted prevalence ratio: 0.66; 95% CI: 0.61, 0.73). This relationship was consistent for the outcome of any bacterial growth.

IMPACT

This repeated cross-sectional analysis of a nationally representative retail meat surveillance database in the United States supports that retail meats labeled with antibiotic restriction claims were less likely to be contaminated with MDROs compared with retail meat without such claims during 2016-2019. These findings indicate the potential for the public to become exposed to bacterial pathogens via retail meat and emphasizes a possibility that consumers could reduce their exposure to environmental reservoirs of foodborne pathogens that are resistant to antibiotics.

Recent advances in fluorescence-based chemosensing of organoarsenic feed additives using luminescence MOFs, COFs, HOFs, and QDs

Organoarsenics are low-toxicity compounds that are used widely as feed additives to promote livestock growth, enhance meat pigmentation, and fight against intestinal parasites. The organoarsenic compounds are commonly found in poultry waste and the degradation of organoarsenic produces the toxic carcinogen inorganic arsenic such as As(V) and As(III), which results in severe arsenic pollution of soil and groundwater. As a consequence, there exists a high necessity to develop suitable sensing methods for the trace detection and quantification of organoarsenic feed additives in wastewater. Among various detection methods, in particular, fluorescence-based sensing has become a popular and efficient method used extensively for sensing water contaminants and environmental contaminants. In the recent past, a wide variety of fluorescence chemosensors have been designed and employed for the efficient sensing and quantification of the concentration of organoarsenic feed additives in different environmental samples. This review article systematically highlights various fluorescence chemosensors reported to date for fluorescence-based sensing of organoarsenic feed additives. The fluorescence sensors discussed in this review are classified and grouped according to their structures and functions, and in each section, we provide a detailed report on the structure, photophysics, and fluorescence sensing properties of different chemosensors. Lastly, the future perspectives on the design and development of practically useful sensor systems for selective and discriminative sensing of organoarsenic compounds have been stated.

Jacob-induced transcriptional inactivation of CREB promotes Aβ-induced synapse loss in Alzheimer's disease

Synaptic dysfunction caused by soluble β-amyloid peptide (Aβ) is a hallmark of early-stage Alzheimer's disease (AD), and is tightly linked to cognitive decline. By yet unknown mechanisms, Aβ suppresses the transcriptional activity of cAMP-responsive element-binding protein (CREB), a master regulator of cell survival and plasticity-related gene expression. Here, we report that Aβ elicits nucleocytoplasmic trafficking of Jacob, a protein that connects a NMDA-receptor-derived signalosome to CREB, in AD patient brains and mouse hippocampal neurons. Aβ-regulated trafficking of Jacob induces transcriptional inactivation of CREB leading to impairment and loss of synapses in mouse models of AD. The small chemical compound Nitarsone selectively hinders the assembly of a Jacob/LIM-only 4 (LMO4)/ Protein phosphatase 1 (PP1) signalosome and thereby restores CREB transcriptional activity. Nitarsone prevents impairment of synaptic plasticity as well as cognitive decline in mouse models of AD. Collectively, the data suggest targeting Jacob protein-induced CREB shutoff as a therapeutic avenue against early synaptic dysfunction in AD.

Diet Sustainability Analyses Can Be Improved With Updates to the Food Commodity Intake Database

Diet sustainability analyses inform policymaking decisions and provide clinicians and consumers with evidence-based information to make dietary changes. In the United States, the Food Commodity Intake Database (FCID) provides a crosswalk for integrating nationally representative data on food intake from the National Health and Nutrition Examination Survey (NHANES) with data on sustainability outcomes from other publicly available databases. However, FCID has not been updated since 2010 and does not link with contemporary NHANES data, which limits further advancements in sustainability research. This study fills this research gap by establishing novel linkages between FCID and NHANES 2011-2018, comparing daily per capita food intake with and without these linkages, and making these data publicly available for use by other researchers. To update FCID, two investigators independently established novel data linkages, a third investigator resolved discrepancies, and a fourth investigator audited linkages for accuracy. Dietary data were acquired from nearly 45,000 adults from 2001 to 2018, and food intake was compared between updated vs. non-updated FCID versions. Total food intake from 2011 to 2018 was 5-23% higher using the updated FCID compared to the non-updated version, and intake was over 100% higher in some years for some food categories including poultry, eggs, legumes, starchy vegetables, and tropical oils (P < 0.001 for all comparisons). Further efforts may be needed to create new food composition data to reflect new products and reformulations that enter the food supply over time. This study removes a barrier to further diet sustainability analyses by establishing a data crosswalk between contemporary NHANES and other publicly available databases on agricultural resource use, environmental impacts, and consumer food expenditures.

Phenylarsonics in concentrated animal feeding operations: Fate, associated risk, and treatment approaches

Phenylarsonics are present as additives in animal feed in some countries. As only a small fraction of these additives is metabolized in animals, they mostly end up in the environment. A comprehensive investigation of the fate of these additives is crucial for evaluating their risks. This review aims to provide a clear understanding of the transformation mechanism of phenylarsonics in vivo and in vitro and to evaluate their fate and associated risks. Degradation of phenylarsonics releases toxic As species (mainly as inorganic arsenic (iAs)). Trivalent phenylarsonics are the metabolites or biotic degradation intermediates of phenylarsonics. The cleavage of As groups from trivalent phenylarsonics catalyzed by C-As lyase or other unknown pathways generates arsenite (As(III)). As(III) can be further oxidized to arsenate (As(V)) and methylated to methyl-arsenic species. The half-lives associated with abiotic degradation of phenylarsonics ranged from a few minutes to tens of hours, while those associated with biotic degradation ranged from several days to hundreds of days. Abiotic degradation resulted in a higher yield of iAs than biotic degradation. The use of phenylarsonics led to elevated total As and iAs levels in animal products and environmental matrices, resulting in As exposure risk to humans. The oxidation of phenylarsonics to As(V) facilitated the sorptive removal of As, which provides a general approach for treating these compounds. This review provides solid evidence that the use of phenylarsonics has adverse effects on both human health and environmental safety, and therefore, supports their withdrawal from the global market.

Pollution characteristics and health risk assessment of arsenic transformed from feed additive organoarsenicals around chicken farms on the North China Plain

Arsenic is frequently found in poultry waste, most of which is transformed from feed additive organoarsenicals, resulting in arsenic pollution of soils and water around poultry farms. The North China Plain, an important area for livestock breeding of China, was chosen to investigate the pollution characteristics and assess the health risk of arsenic around chicken farms. Among the 138 chicken farms sampled, almost no roxarsone, a common organoarsenical, was detected in chicken feeds, manure, and surface soils, while the detectable rate of other arsenic species was high. Because of long-term enrichment, the concentrations of arsenic species in manure were generally higher than that in feed. As(III) was the main inorganic arsenic species in the manure, where is reducing environment. In surface soils beneath the accumulated manure, As(V) was the predominant arsenic species with 100% detectable rate. The detectable rate and average concentrations at 0 cm were generally higher than those at 25 cm depth, indicating that arsenic accumulated in the surface soils. In addition, a typical conceptual diagram of arsenic was developed to clarify the pollution process from feed to soil. Through health risk assessment of inorganic arsenic, the carcinogenic risk (CR) and non-carcinogenic risk (non-CR) were both negligible. The city of Jiaozuo had the highest CR and non-CR, which was 11 times higher than that of the city with the lowest risks. This study presents a clear picture and evaluation of arsenic pollution on chicken farms, inspiring future studies assessing arsenic pollution after the ban of organoarsenicals.

Arsenic: Various species with different effects on cytochrome P450 regulation in humans

Arsenic is well-recognized as one of the most hazardous elements which is characterized by its omnipresence throughout the environment in various chemical forms. From the simple inorganic arsenite (iAsIII) and arsenate (iAsV) molecules, a multitude of more complex organic species are biologically produced through a process of metabolic transformation with biomethylation being the core of this process. Because of their differential toxicity, speciation of arsenic-based compounds is necessary for assessing health risks posed by exposure to individual species or co-exposure to several species. In this regard, exposure assessment is another pivotal factor that includes identification of the potential sources as well as routes of exposure. Identification of arsenic impact on different physiological organ systems, through understanding its behavior in the human body that leads to homeostatic derangements, is the key for developing strategies to mitigate its toxicity. Metabolic machinery is one of the sophisticated body systems targeted by arsenic. The prominent role of cytochrome P450 enzymes (CYPs) in the metabolism of both endobiotics and xenobiotics necessitates paying a great deal of attention to the possible effects of arsenic compounds on this superfamily of enzymes. Here we highlight the toxicologically relevant arsenic species with a detailed description of the different environmental sources as well as the possible routes of human exposure to these species. We also summarize the reported findings of experimental investigations evaluating the influence of various arsenicals on different members of CYP superfamily using human-based models.

Diet: A Source of Endocrine Disruptors

BACKGROUND

Food is indispensable for human life and determines the health and wellbeing of the consumer. As food is the source of energy for humans, it also emerges as one of the most important sources of exposure to deleterious chemicals both natural and synthetic. The food exposed chemicals cause a number of detrimental health effects in humans, with endocrine disruption being of serious concern amongst these effects. Such chemicals disrupting the health of endocrine system are known as endocrine-disrupting chemicals (EDCs). The food exposed EDCs need to be identified and classified to effectuate a cautious consumption of food by all and especially by vulnerable groups.

AIM

The aim of the present review was to discuss food as a source of exposure to common endocrine disruptors in humans. This review presents the occurrence and levels of some of the critical endocrine disruptors exposed through frequently consumed diets.

METHODS

The major source of data was PubMed, besides other relevant publications. The focus was laid on data from the last five years, however significant earlier data was also considered.

CONCLUSION

The food as a source of endocrine disruptors to humans cannot be neglected. It is highly imperative for the consumer to recognize food as a source of EDCs and make informed choices in the consumption of food items.

Screening of hub genes and prediction of putative drugs in arsenic-related bladder carcinoma: An in silico study

BACKGROUND

Evidence showed that inorganic arsenic (iAs) can trigger malignant transformation in cells with complex mechanisms. Thus, we aimed to investigate the possible molecules, pathways and therapeutic drugs for iAs-induced bladder cancer (BC) by using bioinformatics approaches.

METHODS

Microarray-based data were analyzed to screen the differentially expressed genes (DEGs) between iAs-related BC cells and controls. Then, the roles of DEGs were annotated and the hub genes were screened out by protein-protein interaction network. The key genes were further selected from the hub genes through an assessment of the prognostic values. Afterward, potential drugs were predicted by using CMAP analysis.

RESULTS

Analysis of a dataset (GSE90023) generated 21 upregulated and 47 downregulated DEGs, which were enriched in various signaling pathways. Among the DEGs, four hub genes including WNT7B, SFRP1, DNAJB2, and ATF3, were identified as the key genes because they might predict poor prognosis in BC patients. Lastly, Cantharidin was predicted to be a potential drug reversing iAs-induced malignant transformation in urinary epithelium cells.

CONCLUSION

The present study found several hub genes involved in iAs-induced malignant transformation in urinary epithelium cells, and predicted several small agents for iAs toxicity prevention or therapy.

Antimicrobial Resistance in Agri-Food Chain and Companion Animals as a Re-emerging Menace in Post-COVID Epoch: Low-and Middle-Income Countries Perspective and Mitigation Strategies

Antimicrobial resistance (AMR) leads to enormous financial losses from issues such as high morbidity, mortality, man-days lost, hospital length of stay, health-care, and social costs. In humans, over prescription of antimicrobials, which is presumably higher during COVID, has been identified as the major source of selection for antimicrobial resistant bacteria; however, use of antimicrobials in food and companion animals, fish, and vegetables, and the environmental resistance gene pool, also play important roles. The possibilities of unnecessary use of antibiotics as prophylaxis during and after COVID in livestock and companion animals exist in low-and middle-income countries. A considerable loss in gross domestic product (GDP) is also projected in low-and middle-income countries (LMICs) due to AMR by the year 2050, which is further going to be reduced due to economic slowdown in the post-COVID period. Veterinary hospitals dedicated to pets have cropped up, especially in urban areas of LMICs where use of antimicrobials has also been increased substantially. The inevitable preventive habit built up during COVID with the frequent use of hand sanitizer might trigger AMR due to the presence of cross-resistance with disinfectants. In LMICs, due to the rising demand for animal protein, industrial food animal production (IFAP) is slowly replacing the small-scale backyard farming system. The lack of stringent regulations and monitoring increased the non-therapeutic use of antimicrobials in industrial farms where the persistence of antimicrobial resistant bacteria has been associated with several factors other than antimicrobial use, such as co-resistance, cross-resistance, bacterial fitness, mixing of new and old animals, and vectors or reservoirs of bacterial infection. The present review describes types of antimicrobials used in agri-food chains and companion animals in LMICs with identification of the gap in data, updated categories of prevalent antimicrobial resistant bacteria, the role of animal farms as reservoirs of resistant bacteria, and mitigation strategies, with a special focus on the pivotal strategy needed in the post-COVID period.

Assessing inorganic arsenic in rice and its health risk to consumers in Ho Chi Minh City, Vietnam

Purpose

The consumption of rice that contains high levels of inorganic arsenic may cause human health risk. This study aims to determine As species concentrations, particularly iAs, in raw rice in Ho Chi Minh (HCM) City and its health risks.

Design/methodology/approach

A total of 60 polished raw composite samples of rice were purchased from traditional markets and supermarkets in HCM City. All samples were analyzed by HPLC-ICPMS for As species determination.

Findings

Mean concentrations of inorganic arsenic in all samples, which were purchased from supermarket and traditional market, were 88.8 µg/kg and 80.6 µg/kg, respectively. Overall, inorganic arsenic level was 84.7 µg/kg and contributed the highest proportion of arsenic species in rice with 67.7%. The proportion profiles for arsenic species were: As (III) (60 %); dimethylarsinic acid (32.2 %); As (V) (7.7 %) and methylarsonic acid (0.1 %). Inorganic arsenic level in raw rice was below the recommendation of World Health Organization. Using the benchmark dose recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), all exposure doses were lower than BMDL05. However, as the doses ranged from 3.0 to 8.6 of Margin of Exposure (MOE), the health risk of iAs from rice consumption remains public health concern.

Originality/value

The study results report on the surveillance data of the presence of inorganic arsenic in raw rice products, which are available in the supermarkets and traditional markets, and its health risk to consumers in a metropolitan city in Vietnam.

Arsenic intoxication: general aspects and chelating agents

Arsenic (As) is widely used in the modern industry, especially in the production of pesticides, herbicides, wood preservatives, and semiconductors. The sources of As such as contaminated water, air, soil, but also food, can cause serious human diseases. The complex mechanism of As toxicity in the human body is associated with the generation of free radicals and the induction of oxidative damage in the cell. One effective strategy in reducing the toxic effects of As is the usage of chelating agents, which provide the formation of inert chelator–metal complexes with their further excretion from the body. This review discusses different aspects of the use of metal chelators, alone or in combination, in the treatment of As poisoning. Consideration is given to the therapeutic effect of thiol chelators such as meso-2,3-dimercaptosuccinic acid, sodium 2,3-dimercapto-1-propanesulfonate, 2,3-dimercaptopropanol, penicillamine, ethylenediaminetetraacetic acid, and other recent agents against As toxicity. The review also considers the possible role of flavonoids, trace elements, and herbal drugs as promising natural chelating and detoxifying agents.

Arsanilic acid contributes more to total arsenic than roxarsone in chicken meat from Chinese markets

Organoarsenicals have been used in poultry production for years, however, studies focused on roxarsone (ROX), with little attention to p-arsanilic acid (ASA). We assessed arsenic (As) concentration and speciation in chicken meat collected from 10 cities in China. The geometric mean for total As in 249 paired raw and cooked samples was 4.85 and 7.27 μg kg^-1 fw, respectively. Among 81 paired raw and cooked samples, ASA and ROX were detected in >90% samples, suggesting the prevalence of organoarsenical use in China. ASA contributed the most (45% on average) to total As in cooked samples, followed by As(V), DMA, As(III), and ROX (7.2-22%). ASA was found to contribute more to total As in chicken meat compared to ROX for the first time. Arsenic in chicken meat showed considerable geographic variation, with higher inorganic arsenic (iAs) being detected from cities with higher ROX and ASA, indicating that organoarsenical use increased iAs concentration in chicken meat. When health risk was estimated, dietary exposure to iAs would result in an increase of 3.2 bladder and lung cancer cases per 100,000 adults. The result supports the removal of organoarsenicals in poultry production from Chinese market and further supports its removal from the global markets.

VEGF/Flk1 Mechanism is Involved in Roxarsone Promotion of Rat Endothelial Cell Growth and B16F10 Xenograft Tumor Angiogenesis

The potential angiogenic effect of roxarsone, a feed additive widely used to promote animal growth worldwide, was demonstrated recently. We explored the mechanism of vascular endothelial growth factor (VEGF) and its receptor (VEGFR) in roxarsone promotion of rat vascular endothelial cells (ECs) and B16F10 mouse xenografts. ECs were treated with 0.1–50 μM roxarsone or with roxarsone plus 10 ng/mL VEGF, VEGFR1 (Flt1), or VEGFR2 (Flk1) antibodies for 12–48 h to examine their role in cell growth promotion. Small interfering RNA (siRNA) targeting Vegf, Flt1, and Flk1 were transfected in the ECs, and we measured the expression level, cell proliferation, migration, and tube formation ability. The siRNA targeting Vegf or Flk1 were injected intratumorally in the B16F10 xenografts of mice that received 25 mg/kg roxarsone orally. Cell viability and VEGF expression following roxarsone treatment were significantly higher than that of the control (P < 0.05), peaking following treatment with 1.0 μM roxarsone. Compared to roxarsone alone, the VEGF antibody decreased cell promotion by roxarsone (P < 0.05), and the Flk1 antibody greatly reduced cell viability compared to the Flt1 antibody (P < 0.01). Roxarsone and Flk1 antibody co-treatment increased supernatant VEGF significantly, while cellular VEGF was obviously decreased (P < 0.01), whereas there was no significant difference following Flt1 antibody blockade. The siRNA against Vegf or Flk1 significantly attenuated the roxarsone promotion effects on EC proliferation, migration, and tube-like formation (P < 0.01), whereas the siRNA against Flt1 effected no obvious differences. Furthermore, the RNA interference significantly weakened the roxarsone-induced increase in xenograft weight and volume, and VEGF and Flk1 expression. Roxarsone promotion of rat EC growth, migration, and tube-like formation in vitro and of B16F10 mouse xenograft model tumor growth and angiogenesis involves a VEGF/Flk1 mechanism.

China's Ban on Phenylarsonic Feed Additives, A Major Step toward Reducing the Human and Ecosystem Health Risk from Arsenic

Phenylarsonic feed additives were once widely used in poultry and swine production around the world, which brought significant and unnecessary health risk to consumers due to elevated residues of arsenic species in animal tissues. They also increased the risk to ecosystems via releases of inorganic arsenic through their environmental transformation. Out of concern for the negative impacts on human and ecosystem health, China, one of the world's largest poultry and swine producing countries, recently banned the use of phenylarsonic feed additives in food animal production. This ban, if fully enforced, will result in reduction of approximately 1160 cancer cases per year from the consumption of chicken meat alone, and avoid an annual economic loss of nearly 0.6 billion CNY according to our risk analysis. Furthermore, the inventory of anthropogenic arsenic emissions in China will be cut by approximately one-third with the phase-out of phenylarsonic feed additives. This ban is also expected to lead to significant reduction in the accumulation of arsenic in the soils of farmlands fertilized by poultry and swine wastes and, consequently, lower the accumulation of arsenic in food crops grown on them, which could have even greater public health benefits. But effective enforcement of the ban is crucial, and it will require detailed supervision of veterinary drug production and distribution, and enhanced surveillance of animal feeds and food products. Furthermore, control of other major anthropogenic sources of arsenic is also necessary to better protect human health and the environment.

Applying an environmental public health lens to the industrialization of food animal production in ten low- and middle-income countries

Background

Industrial food animal production (IFAP) is characterized by dense animal housing, high throughput, specialization, vertical integration, and corporate consolidation. Research in high-income countries has documented impacts on public health, the environment, and animal welfare. IFAP is proliferating in some low- and middle-income countries (LMICs), where increased consumption of animal-source foods has occurred alongside rising incomes and efforts to address undernutrition. However, in these countries IFAP’s negative externalities could be amplified by inadequate infrastructure and resources to document issues and implement controls.

Methods

Using UN FAOSTAT data, we selected ten LMICs where food animal production is expanding and assessed patterns of IFAP growth. We conducted a mixed methods review to explore factors affecting growth, evidence of impacts, and information gaps; we searched several databases for sources in English, Spanish, and Portuguese. Data were extracted from 450+ sources, comprising peer-reviewed literature, government documents, NGO reports, and news articles.

Results

In the selected LMICs, not only has livestock production increased, but the nature of expansion appears to have involved industrialized methods, to varying extents based on species and location. Expansion was promoted in some countries by explicit government policies. Animal densities, corporate structure, and pharmaceutical reliance in some areas mirrored conditions found in high-income countries. There were many reported weaknesses in regulation and capacity for enforcement surrounding production and animal welfare. Global trade increasingly influences movement of and access to inputs such as feed. There was a nascent, compelling body of scientific literature documenting IFAP’s negative environmental and public health externalities in some countries.

Conclusions

LMICs may be attracted to IFAP for economic development and food security, as well as the potential for increasing access to animal-source foods and the role these foods can play in alleviating undernutrition. IFAP, however, is resource intensive. Industrialized production methods likely result in serious negative public health, environmental, and animal welfare impacts in LMICs. To our knowledge, this is the first systematic effort to assess IFAP trends through an environmental public health lens for a relatively large group of LMICs. It contributes to the literature by outlining urgent research priorities aimed at informing national and international decisions about the future of food animal production and efforts to tackle global undernutrition.

Role of ArsEFG in Roxarsone and Nitarsone Detoxification and Resistance

Organoarsenical biotransformations are important components of the global cycling of arsenic. Roxarsone (3-nitro-4-hydroxybenzenearsenate or Rox(V)) and nitarsone (4-nitrobenzene arsenate or Nit(V)) are synthetic aromatic organoarsenicals used in the poultry industry as additives to prevent coccidiosis and improve feed efficiency. Here, we describe a novel pathway of resistance to roxarsone and nitarsone involving biotransformation of their trivalent forms (Rox(III)) and (Nit(III)) to the trivalent organoarsenicals HAPA(III) and pAsA(III), coupled to active extrusion of the aromatic aminobenezylarsenicals from the cells. The arsE, arsF, and arsG were cloned from the arsenic island in the chromosome of Shewanella putrefaciens 200. When expressed in Escherichia coli together, but not alone, arsEFG conferred resistance to Rox(III) and Nit(III) and decreased the accumulation of both. The cells transformed Rox(III) or Nit(III) to HAPA(III) or pAsA(III) by reducing the nitro group to an amine. Everted membrane vesicles from cells expressing arsG accumulated HAPA(III) or pAsA(III). Our data indicate that ArsE and ArsF together reduce Rox(III) or Nit(III) to HAPA(III) or pAsA(III), which are extruded from the cells by the efflux permease ArsG. Identification of the coupled pathway of ArsE, ArsF, and ArsG catalysis is a molecular description of a novel pathway for resistance to roxarsone and nitarsone.

Ethnic, geographic and dietary differences in arsenic exposure in the multi-ethnic study of atherosclerosis (MESA)

Differences in residential location as well as race/ethnicity and dietary habits may result in differences in inorganic arsenic (iAs) exposure. We investigated the association of exposure to iAs with race/ethnicity, geography, and dietary intake in a random sample of 310 White, Black, Hispanic, and Chinese adults in the Multi-Ethnic Study of Atherosclerosis from 6 US cities with inorganic and methylated arsenic (ΣAs) measured in urine. Dietary intake was assessed by food-frequency questionnaire. Chinese and Hispanic race/ethnicity was associated with 82% (95% CI: 46%, 126%) and 37% (95% CI: 10%, 70%) higher urine arsenic concentrations, respectively, compared to White participants. No differences were observed for Black participants compared to Whites. Urine arsenic concentrations were higher for participants in Los Angeles, Chicago, and New York compared to other sites. Participants that ate rice ≥2 times/week had 31% higher urine arsenic compared to those that rarely/never consumed rice. Participants that drank wine ≥2 times/week had 23% higher urine arsenic compared to rare/never wine drinkers. Intake of poultry or non-rice grains was not associated with urinary arsenic concentrations. At the low-moderate levels typical of the US population, exposure to iAs differed by race/ethnicity, geographic location, and frequency of rice and wine intake.

Risk of exposure to total and inorganic arsenic by meat intake among different age groups from Brazil: a probabilistic assessment

Beef and poultry as well as cattle and chicken livers are staple food items for Brazilian population, and previous studies had detected arsenic levels in these foods. This study aims to evaluate the risk of exposure to total and inorganic arsenic by meat intake in three age groups from Brazil (11-16, 16-21, and > 21 years). Our hypotheses are (i) that there is differences in the risk of exposure between age groups and (ii) the older individuals (> 21 years) are under higher risk. To test these hypotheses, we calculated the probabilistic estimated daily intake of total As (TAs^EDI) from poultry, beef, cattle liver, and chicken liver, and the probabilistic estimated incremental lifetime skin, bladder, and lung cancer risk (ILCR) associated with inorganic As ingestion from poultry only. TAs^EDI and ILCR from poultry differed among groups which confirm the first hypothesis. However, TAs^EDI and ILCR results cannot support the second hypothesis. Even though the age groups are under a low risk of exposure to As by meat intake, the results indicate that bladder/lung cancer risk (from poultry intake) slightly exceeds the safe limits in the older population.

Public health risk of trace metals in fresh chicken meat products on the food markets of a major production region in southern China

Because most chickens are reared in intensive farms, where a range of feed additives are used routinely, concerns have been raised on the potential public health risk of chicken product consumption. This study was conducted to characterize the contents of trace metals in fresh chicken tissues (354 samples) on the food markets in Guangdong province of southern China, a major region of chicken production with heavy per capita chicken consumption, and to assess the public health risk from chronic dietary exposure to the trace metals through chicken consumption. With the exception of Cr, Ni, and Pb, the contents of trace metals were generally higher in the chicken giblets (livers, gizzards, hearts, and kidneys) compared to muscles (breasts and drumsticks). Chicken tissues from the urban markets generally contained higher levels of As, Cu, Mn, and Zn than those from the rural markets, while the contents of Pb were typically higher in the chicken muscles from the rural markets. Results of statistical analyses indicate that Cu, Zn, and As in the chicken tissues derived mainly from the feeds, which is consistent with the widespread use of Cu, Zn, and phenylarsenic compounds as feed supplements/additives in intensive poultry farming. No non-carcinogenic risk is found with the consumption of fresh chicken meat products on the food markets, while approximately 70% of the adult population in Guangzhou and 30% of those in Lianzhou have bladder and lung cancer risk above the serious or priority level (10^-4), which arises from the inorganic arsenic contained in the chicken tissues. These findings indicate that the occurrence of inorganic arsenic at elevated levels in chicken tissues on the food markets in Guangdong province poses a significant public health risk, thus the use of phenylarsenic feed additives in China's poultry farming should be significantly reduced and eventually phased out.

Biochemical Characterization of ArsI: A Novel C-As Lyase for Degradation of Environmental Organoarsenicals

Organoarsenicals such as the methylarsenical methylarsenate (MAs(V)) and aromatic arsenicals including roxarsone (4-hydroxy-3-nitrobenzenearsenate or Rox(V)) have been extensively used as an herbicide and growth enhancers in animal husbandry, respectively. They undergo environmental degradation to more toxic inorganic arsenite (As(III)) that contaminates crops and drinking water. We previously identified a bacterial gene (arsI) responsible for aerobic demethylation of methylarsenite (MAs(III)). The gene product, ArsI, is an Fe(II)-dependent extradiol dioxygenase that cleaves the carbon-arsenic (C-As) bond in MAs(III) and in trivalent aromatic arsenicals. The objective of this study was to elucidate the ArsI mechanism. Using isothermal titration calorimetry, we determined the dissociation constants and ligand-to-protein stoichiometry of ArsI for Fe(II), MAs(III), and aromatic phenylarsenite. Using a combination of methods including chemical modification, site-directed mutagenesis, and fluorescent spectroscopy, we demonstrated that amino acid residues predicted to participate in Fe(II)-binding (His5-His62-Glu115) and substrate binding (Cys96-Cys97) are involved in catalysis. Finally, the products of Rox(III) degradation were identified as As(III) and 2-nitrohydroquinone, demonstrating that ArsI is a dioxygenase that incorporates one oxygen atom from dioxygen into the carbon and the other to the arsenic to catalyze cleavage of the C-As bond. These results augment our understanding of the mechanism of this novel C-As lyase.

Poultry Consumption and Arsenic Exposure in the U.S. Population

BACKGROUND

Arsenicals (roxarsone and nitarsone) used in poultry production likely increase inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and roxarsone or nitarsone concentrations in poultry meat. However, the association between poultry intake and exposure to these arsenic species, as reflected in elevated urinary arsenic concentrations, is unknown.

OBJECTIVES

Our aim was to evaluate the association between 24-hr dietary recall of poultry consumption and arsenic exposure in the U.S. population. We hypothesized first, that poultry intake would be associated with higher urine arsenic concentrations and second, that the association between turkey intake and increased urine arsenic concentrations would be modified by season, reflecting seasonal use of nitarsone.

METHODS

We evaluated 3,329 participants ≥ 6 years old from the 2003-2010 National Health and Nutrition Examination Survey (NHANES) with urine arsenic available and undetectable urine arsenobetaine levels. Geometric mean ratios (GMR) of urine total arsenic and DMA were compared across increasing levels of poultry intake.

RESULTS

After adjustment, participants in the highest quartile of poultry consumption had urine total arsenic 1.12 (95% CI: 1.04, 1.22) and DMA 1.13 (95% CI: 1.06, 1.20) times higher than nonconsumers. During the fall/winter, participants in the highest quartile of turkey intake had urine total arsenic and DMA 1.17 (95% CI: 0.99, 1.39; p-trend = 0.02) and 1.13 (95% CI: 0.99, 1.30; p-trend = 0.03) times higher, respectively, than nonconsumers. Consumption of turkey during the past 24 hr was not associated with total arsenic or DMA during the spring/summer.

CONCLUSIONS

Poultry intake was associated with increased urine total arsenic and DMA in NHANES 2003-2010, reflecting arsenic exposure. Seasonally stratified analyses by poultry type provide strong suggestive evidence that the historical use of arsenic-based poultry drugs contributed to arsenic exposure in the U.S.

CITATION

Nigra AE, Nachman KE, Love DC, Grau-Perez M, Navas-Acien A. 2017. Poultry consumption and arsenic exposure in the U.S. Environ Health Perspect 125:370-377; http://dx.doi.org/10.1289/EHP351.

Mitigating dietary arsenic exposure: Current status in the United States and recommendations for an improved path forward

Inorganic arsenic (iAs) is a well-characterized carcinogen, and recent epidemiologic studies have linked chronic exposures to non-cancer health outcomes, including cardiovascular disease, diabetes, skin lesions and respiratory disorders. Greater vulnerability has been demonstrated with early life exposure for health effects including lung and bladder cancer, immunotoxicity and neurodevelopment. Despite its well-known toxicity, there are important gaps in the regulatory oversight of iAs in food and in risk communication. This paper focuses on the US regulatory framework in relation to iAs in food and beverages. The state of existing regulatory agency toxicological assessments, monitoring efforts, standard setting, intervention policies and risk communication are explored. Regarding the approach for standard setting, risk-based evaluations of iAs in particular foods can be informative but are insufficient to create a numeric criterion, given current uncertainties in iAs toxicology and the degree to which traditional risk targets can be exceeded by dietary exposures. We describe a process for prioritizing dietary exposures for different lifestages and recommend a relative source contribution-based approach to setting criteria for arsenic in prioritized foods. Intervention strategies begin with an appropriately set criterion and a monitoring program that documents the degree to which this target is met for a particular food. This approach will promote improvements in food production to lower iAs contamination for those foods which initially do not meet the criterion. Risk communication improvements are recommended to ensure that the public has reliable information regarding sources and alternative dietary choices. A key recommendation is the consideration of meal frequency advice similar to what is currently done for contaminants in fish. Recent action level determinations by FDA for apple juice and infant rice cereal are evaluated and used as illustrations of how our recommended approach can further the goal of exposure mitigation from key sources of dietary iAs in the US.