Obfuscating transparency?

Several recent and prominent articles in Science and Nature deliberately mischaracterized the nature of genuine scientific evidence. Those articles take issue with the United States Environmental Protection Agency's recent proposal to structure its policies and rules only from studies with transparently published raw data. The articles claim it is an effort to obfuscate with transparency, by eliminating a host of studies not offering raw data. A remarkable declaration by a Science editorial is that properly trained experts can verify the scientific evidence of studies without access to raw data, We assert the Agency's proposal must be sustained. Transparency in reporting is a fundamental ethical imperative of objective scientific research justifying massive official regulations and policies. Putative hazards bereft of independent scientific evidence will continue to stoke public anxieties, calling for precautionary regulations and policies. These should rely not on spurious science but on transparent tradeoffs between the smallest exposures compatible with utility and with social perceptions of affordable precaution.

A review of the carcinogenic potential of glyphosate by four independent expert panels and comparison to the IARC assessment.

The International Agency for Research on Cancer (IARC) published a monograph in 2015 concluding that glyphosate is "probably carcinogenic to humans" (Group 2A) based on limited evidence in humans and sufficient evidence in experimental animals. It was also concluded that there was strong evidence of genotoxicity and oxidative stress. Four Expert Panels have been convened for the purpose of conducting a detailed critique of the evidence in light of IARC's assessment and to review all relevant information pertaining to glyphosate exposure, animal carcinogenicity, genotoxicity, and epidemiologic studies. Two of the Panels (animal bioassay and genetic toxicology) also provided a critique of the IARC position with respect to conclusions made in these areas. The incidences of neoplasms in the animal bioassays were found not to be associated with glyphosate exposure on the basis that they lacked statistical strength, were inconsistent across studies, lacked dose-response relationships, were not associated with preneoplasia, and/or were not plausible from a mechanistic perspective. The overall weight of evidence from the genetic toxicology data supports a conclusion that glyphosate (including GBFs and AMPA) does not pose a genotoxic hazard and therefore, should not be considered support for the classification of glyphosate as a genotoxic carcinogen. The assessment of the epidemiological data found that the data do not support a causal relationship between glyphosate exposure and non-Hodgkin's lymphoma while the data were judged to be too sparse to assess a potential relationship between glyphosate exposure and multiple myeloma. As a result, following the review of the totality of the evidence, the Panels concluded that the data do not support IARC's conclusion that glyphosate is a "probable human carcinogen" and, consistent with previous regulatory assessments, further concluded that glyphosate is unlikely to pose a carcinogenic risk to humans.

Upholding science in health, safety and environmental risk assessments and regulations.

A public appeal has been advanced by a large group of scientists, concerned that science has been misused in attempting to quantify and regulate unmeasurable hazards and risks.1 The appeal recalls that science is unable to evaluate hazards that cannot be measured, and that science in such cases should not be invoked to justify risk assessments in health, safety and environmental regulations. The appeal also notes that most national and international statutes delineating the discretion of regulators are ambiguous about what rules of evidence ought to apply. Those statutes should be revised to ensure that the evidence for regulatory action is grounded on the standards of the scientific method, whenever feasible. When independent scientific evidence is not possible, policies and regulations should be informed by publicly debated trade-offs between socially desirable uses and social perceptions of affordable precaution. This article explores the premises, implications and actions supporting the appeal and its objectives.

Research needs to improve risk assessment of fiber toxicity.

Risk characterization of exposure to toxic compounds requires information on the intrinsic toxic properties, including toxic mechanism and toxicokinetics, on dose response at the most critical targets for identification of the NOEL or for extrapolation from high to low dose, and on human exposure. Abundant information is available on the intrinsic properties of MMMF, on the three D's (dose, dimension, durability) and on the toxic mechanisms. However, only a few of these studies provide information on the dose response of the effects or of the mechanisms investigated. Moreover, in many cases single high doses exceeding the MTD have been applied and are difficult to interpret for lower exposure scenarios. Risk characterization is further hampered by the still open question whether MMMF are directly genotoxic or induce secondary genotoxicity via inflammation. Finally, there is disagreement about the relevance of animal studies on MMMF for humans and thus about the most rational extrapolation of the dose response of toxic effects observed in animals to man. These deficits are briefly described and discussed from a toxicological point of view.

The endocrine and reproductive system: adverse effects of hormonally active substances?

Chemicals that have the intrinsic property to modulate or even disrupt the endocrine system are present in the human environment. Because it is the potency of such chemicals that determines the toxicologic relevance, assessment of the risk to human health must consider both the endocrine disrupting potential and the potency. Usually in vitro assays are applied to detect the potential of a hormone-like effect, and such data are considered useful to set priorities for additional testing and for mechanistic studies. However, such data allow only determination of relative potency of a chemical as compared with other xenobiotics, natural compounds, or endogenous hormones. Relevant information on the endocrine-disrupting potency can be taken only from in vivo assays, eg, the Hershberger (male reproductive organs) and uterotrophic (female reproductive organs) assays, the updated versions of the 28- and 90-day toxicity studies in rodents, and the 2-generation studies in rodents. With the use of this information and the concentration of these chemicals in humans, the potency of the effect as compared with endogenous hormone activity can be estimated. So far, the relative potencies of chemicals tested in in vitro systems as compared with estradiol are several orders of magnitude smaller, whereas potency of the phytoestrogen, eg, isoflavones such as genistein or daidzein, can even exceed that of estradiol, especially in infants who are fed soy-based formula as a sole source of nutrition. Although there are still open questions regarding in utero or early postnatal exposure, the low potencies and concentrations of manmade chemicals as compared with the endogenous hormones in humans make it unlikely that adverse effects occur at common exposure.

The safety assessment of fragrance materials.

Safety evaluation of the large number of diverse chemicals used as fragrance ingredients follows a systematic prioritization of data generation and analysis, consideration of exposure and critical analysis of the quality of the available information. In prior publications the research priorities used by the Research Institute for Fragrance Materials (RIFM), and the methods of exposure estimation used by industry have been summarized. This paper provides details of the approach used by the RIFM Expert Panel (REXPAN), to examine the dermal effects, systemic toxicity and environmental consequences of the use of and exposure to fragrance materials, which allow a reliable determination of safe use under intended conditions. The key to the usefulness of this analysis is the grouping of more than 2600 discrete ingredients into classes, based on chemical structures. Research sponsored by RIFM, data supplied by member companies, and relevant published reports from many sources are all considered during hazard characterization. A discussion is provided of REXPAN's decision tree approach to assessing the dermal, systemic and environmental endpoints and the types and quality of data included. This overall process results in well-documented conclusions which are provided to the International Fragrance Association (IFRA) as the basis for consideration of a new or existing Fragrance Material Standard and to industry for appropriate product risk management actions.