Correction to: Mercury exposure, nutritional deficiencies and metabolic disruptions may affect learning in children.

The original version of this article [1] unfortunately contained an error which has since been acknowledged in this Correction article. The URL link in the Reference 19 was broken and it needs to be replaced with the active link given below.

Exporting obesity: US farm and trade policy and the transformation of the Mexican consumer food environment.

Obesity has reached epidemic proportions, in the United States as well as among its trade partners such as Mexico. It has been established that an "obesogenic" (obesity-causing) food environment is one influence on obesity prevalence. To isolate the particular role of NAFTA, the North American Free Trade Agreement, in changing Mexico's food environment, we plotted the flow of several key products between the United States and Mexico over the 14-year NAFTA period (1994-2008) and situated them in a broader historical context. Key sources of USDA data include the Foreign Agricultural Service's Global Agricultural Trade System, its official repository for current and historical data on imports, exports and re-exports, and its Production, Supply, and Distribution online database. US export data were queried for agricultural products linked to shifting diet patterns including: corn, soybeans, sugar and sweeteners, consumer-oriented products, and livestock products. The Bureau of Economic Analysis' Balance of Payments and Direct Investment Position Data in their web-based International Economic Accounts system also helped determine changes in US direct investment abroad from 1982 to 2009. Directly and indirectly, the United States has exported increasing amounts of corn, soybeans, sugar, snack foods, and meat products into Mexico over the last two decades. Facilitated by NAFTA, these exports are one important way in which US agriculture and trade policy influences Mexico's food system. Because of significant US agribusiness investment in Mexico across the full spectrum of the latter's food supply chain, from production and processing to distribution and retail, the Mexican food system increasingly looks like the industrialized food system of the United States.

A Review of the Effectiveness of Current US Policies on Antimicrobial Use in Meat and Poultry Production.

PURPOSE: Industrial food animal production accounts for most animal-source protein consumed in the USA. These operations rely on an array of external inputs, which can include antimicrobials of medical importance. The use of these drugs in this context has been the subject of public health debate for decades because their widespread use contributes to the selection for and proliferation of drug-resistant bacteria and their genetic determinants. Here, we describe legislative and regulatory efforts, at different levels of governance in the USA, to curtail food animal consumption of medically important antimicrobials. RECENT FINDINGS: The features and relative success of the US efforts are examined alongside those of selected member states (Denmark and the Netherlands) of the European Union. Evaluation of efforts at all levels of US governance was complicated by shortcomings in prescribed data collection; nevertheless, available information suggests deficiencies in policy implementation and enforcement compromise the effectiveness of interventions pursued to date. The political will, robust systems for collecting and integrating data on antimicrobial consumption and use, and cross-sectoral collaboration that have been integral to the success of efforts in Denmark and The Netherlands have been notably absent in the USA, especially at the federal level.

Mercury exposure, nutritional deficiencies and metabolic disruptions may affect learning in children.

Among dietary factors, learning and behavior are influenced not only by nutrients, but also by exposure to toxic food contaminants such as mercury that can disrupt metabolic processes and alter neuronal plasticity. Neurons lacking in plasticity are a factor in neurodevelopmental disorders such as autism and mental retardation. Essential nutrients help maintain normal neuronal plasticity. Nutritional deficiencies, including deficiencies in the long chain polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid, the amino acid methionine, and the trace minerals zinc and selenium, have been shown to influence neuronal function and produce defects in neuronal plasticity, as well as impact behavior in children with attention deficit hyperactivity disorder. Nutritional deficiencies and mercury exposure have been shown to alter neuronal function and increase oxidative stress among children with autism. These dietary factors may be directly related to the development of behavior disorders and learning disabilities. Mercury, either individually or in concert with other factors, may be harmful if ingested in above average amounts or by sensitive individuals. High fructose corn syrup has been shown to contain trace amounts of mercury as a result of some manufacturing processes, and its consumption can also lead to zinc loss. Consumption of certain artificial food color additives has also been shown to lead to zinc deficiency. Dietary zinc is essential for maintaining the metabolic processes required for mercury elimination. Since high fructose corn syrup and artificial food color additives are common ingredients in many foodstuffs, their consumption should be considered in those individuals with nutritional deficits such as zinc deficiency or who are allergic or sensitive to the effects of mercury or unable to effectively metabolize and eliminate it from the body.

Mercury from chlor-alkali plants: measured concentrations in food product sugar.

Mercury cell chlor-alkali products are used to produce thousands of other products including food ingredients such as citric acid, sodium benzoate, and high fructose corn syrup. High fructose corn syrup is used in food products to enhance shelf life. A pilot study was conducted to determine if high fructose corn syrup contains mercury, a toxic metal historically used as an anti-microbial. High fructose corn syrup samples were collected from three different manufacturers and analyzed for total mercury. The samples were found to contain levels of mercury ranging from below a detection limit of 0.005 to 0.570 micrograms mercury per gram of high fructose corn syrup. Average daily consumption of high fructose corn syrup is about 50 grams per person in the United States. With respect to total mercury exposure, it may be necessary to account for this source of mercury in the diet of children and sensitive populations.

The $64 million question. Invest in good teaching.

University of Minnesota School of Public health, USA.

The role of the environment in pediatric practice in Minnesota: attitudes, beliefs, and practices.

Pediatricians can help limit children's exposures to environmental hazards, but few studies have assessed their comfort with discussing and dealing with environmental health issues. We surveyed the membership of the Minnesota Chapter of the American Academy of Pediatrics to assess pediatricians' attitudes and beliefs about the effect the environment can have on children's health, and to assess their practices in regard to screening for, diagnosing, and treating illnesses related to environmental exposures. Results showed that Minnesota pediatricians agree that children are suffering from preventable illnesses of environmental origin but feel ill-equipped to educate parents about many common exposures and their consequences. Responses also indicated significant demand for education on the subject and for a referral center that can evaluate patients who may be suffering from environmental exposures.

The potential role of concentrated animal feeding operations in infectious disease epidemics and antibiotic resistance.

The industrialization of livestock production and the widespread use of nontherapeutic antimicrobial growth promotants has intensified the risk for the emergence of new, more virulent, or more resistant microorganisms. These have reduced the effectiveness of several classes of antibiotics for treating infections in humans and livestock. Recent outbreaks of virulent strains of influenza have arisen from swine and poultry raised in close proximity. This working group, which was part of the Conference on Environmental Health Impacts of Concentrated Animal Feeding Operations: Anticipating Hazards--Searching for Solutions, considered the state of the science around these issues and concurred with the World Health Organization call for a phasing-out of the use of antimicrobial growth promotants for livestock and fish production. We also agree that all therapeutic antimicrobial agents should be available only by prescription for human and veterinary use. Concern about the risk of an influenza pandemic leads us to recommend that regulations be promulgated to restrict the co-location of swine and poultry concentrated animal feeding operations (CAFOs) on the same site and to set appropriate separation distances.

Public health advocate.

With antimicrobial resistance mounting, an important public health goal is to preserve therapeutic effectiveness of remaining antimicrobials. To that end, fewer antimicrobials should be used in human medicine and in agriculture. Public health initiatives to reduce antimicrobial overuse could benefit from concurrent collection of agricultural usage data; they could aid scientific understanding of the resistance problem and confirm the efficacy of interventions. Data collection in this context should be a priority. However, usage data are nonessential to achieving the public health goal. U.S. regulation of agricultural antimicrobials today is very reliant on risk assessment. While more data can be useful for use in risk assessment, microbial risk assessment itself may not be well suited to the purpose of reducing antimicrobial overuse. Among other recognized shortcomings, current microbial risk assessment models typically fail to account for the essential ecological nature of antimicrobial resistance. This makes it inadequate for fully characterizing the human health or ecological risks of animal antimicrobials. European success at phasing out unnecessary antimicrobial usage in agriculture, on the other hand, has derived from decisions based on public health concerns and political will, and not on the collection of usage data or on the successful completion of a risk assessment.

Vinyl chloride: a case study of data suppression and misrepresentation.

When the U.S. Environmental Protection Agency (EPA) finalized its 2000 update of the toxicological effects of vinyl chloride (VC), it was concerned with two issues: the classification of VC as a carcinogen and the numerical estimate of its potency. In this commentary we describe how the U.S. EPA review of VC toxicology, which was drafted with substantial input from the chemical industry, weakened safeguards on both points. First, the assessment down-plays risks from all cancer sites other than the liver. Second, the estimate of cancer potency was reduced 10-fold from values previously used for environmental decision making, a finding that reduces the cost and extent of pollution reduction and cleanup measures. We suggest that this assessment reflects discredited scientific practices and recommend that the U.S. EPA reverse its trend toward ever-increasing collaborations with the regulated industries when generating scientific reviews and risk assessments.

A Food Systems Approach To Healthy Food And Agriculture Policy.

Food has become a prominent focus of US public health policy. The emphasis has been almost exclusively on what Americans eat, not what is grown or how it is grown. A field of research, policy, and practice activities addresses the food-health-agriculture nexus, yet the work is still often considered "alternative" to the mainstream. This article outlines the diverse ways in which agriculture affects public health. It then describes three policy issues: farm-to-school programming, sustainability recommendations in the Dietary Guidelines for Americans, and antibiotic use in animal agriculture. These issues illustrate the progress, challenges, and public health benefits of taking a food systems approach that brings together the food, agriculture, and public health fields.

In harm's way: toxic threats to child development.

Developmental disabilities result from complex interactions of genetic, toxicologic (chemical), and social factors. Among these various causes, toxicologic exposures deserve special scrutiny because they are readily preventable. This article provides an introduction to some of the literature addressing the effects of these toxicologic exposures on the developing brain. This body of research demonstrates cause for serious concern that commonly encountered household and environmental chemicals contribute to developmental disabilities. The developing brain is uniquely susceptible to permanent impairment by exposure to environmental substances during time windows of vulnerability. Lead, mercury, and polychlorinated biphenyls (PCBs) have been extensively studied and found to impair development at levels of exposure currently experienced by significant portions of the general population. High-dose exposures to each of these chemicals cause catastrophic developmental effects. More recent research has revealed toxicity at progressively lower exposures, illustrating a "declining threshold of harm" commonly observed with improved understanding of developmental toxicants. For lead, mercury, and PCBs, recent studies reveal that background-population exposures contribute to a wide variety of problems, including impairments in attention, memory, learning, social behavior, and IQ. Unfortunately, for most chemicals there is little data with which to evaluate potential risks to neurodevelopment. Among the 3000 chemicals produced in highest volume (over 1 million lbs/yr), only 12 have been adequately tested for their effects on the developing brain. This is a matter of concern because the fetus and child are exposed to untold numbers, quantities, and combinations of substances whose safety has not been established. Child development can be better protected by more precautionary regulation of household and environmental chemicals. Meanwhile, health care providers and parents can play an important role in reducing exposures to a wide variety of known and suspected neurodevelopmental toxicants that are widely present in consumer products, food, the home, and wider community.

Evaluation of the association between maternal smoking, childhood obesity, and metabolic disorders: a national toxicology program workshop review.

BACKGROUND: An emerging literature suggests that environmental chemicals may play a role in the development of childhood obesity and metabolic disorders, especially when exposure occurs early in life. OBJECTIVE: Here we assess the association between these health outcomes and exposure to maternal smoking during pregnancy as part of a broader effort to develop a research agenda to better understand the role of environmental chemicals as potential risk factors for obesity and metabolic disorders. METHODS: PubMed was searched up to 8 March 2012 for epidemiological and experimental animal studies related to maternal smoking or nicotine exposure during pregnancy and childhood obesity or metabolic disorders at any age. A total of 101 studies-83 in humans and 18 in animals-were identified as the primary literature. DISCUSSION: Current epidemiological data support a positive association between maternal smoking and increased risk of obesity or overweight in offspring. The data strongly suggest a causal relation, although the possibility that the association is attributable to unmeasured residual confounding cannot be completely ruled out. This conclusion is supported by findings from laboratory animals exposed to nicotine during development. The existing literature on human exposures does not support an association between maternal smoking during pregnancy and type 1 diabetes in offspring. Too few human studies have assessed outcomes related to type 2 diabetes or metabolic syndrome to reach conclusions based on patterns of findings. There may be a number of mechanistic pathways important for the development of aberrant metabolic outcomes following perinatal exposure to cigarette smoke, which remain largely unexplored. CONCLUSIONS: From a toxicological perspective, the linkages between maternal smoking during pregnancy and childhood overweight/obesity provide proof-of-concept of how early-life exposure to an environmental toxicant can be a risk factor for childhood obesity.

A macroepigenetic approach to identify factors responsible for the autism epidemic in the United States.

The number of children ages 6 to 21 in the United States receiving special education services under the autism disability category increased 91% between 2005 to 2010 while the number of children receiving special education services overall declined by 5%. The demand for special education services continues to rise in disability categories associated with pervasive developmental disorders. Neurodevelopment can be adversely impacted when gene expression is altered by dietary transcription factors, such as zinc insufficiency or deficiency, or by exposure to toxic substances found in our environment, such as mercury or organophosphate pesticides. Gene expression patterns differ geographically between populations and within populations. Gene variants of paraoxonase-1 are associated with autism in North America, but not in Italy, indicating regional specificity in gene-environment interactions. In the current review, we utilize a novel macroepigenetic approach to compare variations in diet and toxic substance exposure between these two geographical populations to determine the likely factors responsible for the autism epidemic in the United States.

MRSA in conventional and alternative retail pork products.

In order to examine the prevalence of Staphylococcus aureus on retail pork, three hundred ninety-five pork samples were collected from a total of 36 stores in Iowa, Minnesota, and New Jersey. S. aureus was isolated from 256 samples (64.8%, 95% confidence interval [CI] 59.9%-69.5%). S. aureus was isolated from 67.3% (202/300) of conventional pork samples and from 56.8% (54/95) of alternative pork samples (labeled "raised without antibiotics" or "raised without antibiotic growth promotants"). Two hundred and thirty samples (58.2%, 95% CI 53.2%-63.1%) were found to carry methicillin-sensitive S. aureus (MSSA). MSSA was isolated from 61.0% (183/300) of conventional samples and from 49.5% (47/95) of alternative samples. Twenty-six pork samples (6.6%, 95% CI 4.3%-9.5%) carried methicillin-resistant S. aureus (MRSA). No statistically significant differences were observed for the prevalence of S. aureus in general, or MSSA or MRSA specifically, when comparing pork products from conventionally raised swine and swine raised without antibiotics, a finding that contrasts with a prior study from The Netherlands examining both conventional and "biologic" meat products. In our study spa types associated with "livestock-associated" ST398 (t034, t011) were found in 26.9% of the MRSA isolates, while 46.2% were spa types t002 and t008--common human types of MRSA that also have been found in live swine. The study represents the largest sampling of raw meat products for MRSA contamination to date in the U.S. MRSA prevalence on pork products was higher than in previous U.S.-conducted studies, although similar to that in Canadian studies.