Boobis et al., 2008
Boobis, A. R., Ossendorp, B. C., Banasiak, U., Hamey, P. Y., Sebestyen, I., & Moretto, A.; “Cumulative risk assessment of pesticide residues in food;” Toxicology Letters, 2008, 180(2), 137-150; DOI: 10.1016/j.toxlet.2008.06.004.
ABSTRACT:
There is increasing need to address the potential risks of combined exposures to multiple residues from pesticides in the diet. The available evidence suggests that the main concern is from dose addition of those compounds that act by the same mode of action. The possibility of synergy needs to be addressed on a case-by-case basis, where there is a biologically plausible hypothesis that it may occur at the levels of residues occurring in the diet. Cumulative risk assessment is a resource-intense activity and hence a tiered approach to both toxicological evaluation and intake estimation is recommended, and the European Food Safety Authority (EFSA) has recently published such a proposal. Where assessments have already been undertaken by some other authority, full advantage should be taken of these, subject of course to considerations of quality and relevance. Inclusion of compounds in a cumulative assessment group (CAG) should be based on defined criteria, which allow for refinement in a tiered approach. These criteria should include chemical structure, mechanism of pesticidal action, target organ and toxic mode of action. A number of methods are available for cumulating toxicity. These are all inter-related, but some are mathematically more complex than others. The most useful methods, in increasing levels of complexity and refinement, are the hazard index, the reference point index, the Relative Potency Factor method and physiologically based toxicokinetic modelling, although this last method would only be considered should a highly refined assessment be necessary. Four possible exposure scenarios are of relevance for cumulative risk assessment, acute and chronic exposure in the context of maximum residue level (MRL)-setting, and in relation to exposures from the actual use patterns, respectively. Each can be addressed either deterministically or probabilistically. Strategies for dealing with residues below the limit of detection, limit of quantification or limit of reporting need to be agreed. A number of probabilistic models are available, but some of there are geographically constrained due to the underlying datasets used in their construction. Guidance on probabilistic modelling needs to be finalised. Cumulative risk assessments have been performed in a number of countries, on organophosphate insecticides alone (USA) or together with carbamates (UK, DK, NL), triazines, chloroacetanilides, carbamates alone (USA), and all pesticides (DE). All identifiable assumptions and uncertainties should be tabulated and evaluated, at least qualitatively. Those likely to have a major impact on the outcome of the assessment should be examined quantitatively. In cumulative risk assessment, it is necessary, as in other risk assessments, for risk managers to consider what level of risk would be considered “acceptable”, for example what percentile of the population should be below the reference value. Criteria for prioritising CAGs for cumulative risk assessment include frequency of detection in monitoring programmes, high usage, high exposure relative to the reference value, large number of compounds (e.g. five or more) in a group. FULL TEXT
Curl et al., 2020
Curl, C. L., Spivak, M., Phinney, R., & Montrose, L.; “Synthetic Pesticides and Health in Vulnerable Populations: Agricultural Workers;” Current Environmental Health Reports, 2020, 7(1), 13-29; DOI: 10.1007/s40572-020-00266-5.
ABSTRACT:
PURPOSE OF REVIEW: This review aims to summarize epidemiological literature published between May 15, 2018, and May 14, 2019, that examines the relationship between exposure to synthetic pesticides and health of agricultural workers.
RECENT FINDINGS: Current research suggests that exposure to synthetic pesticides may be associated with adverse health outcomes. Agricultural workers represent a potentially vulnerable population, due to a combination of unique social and cultural risk factors as well as exposure to hazards inherent in agricultural work. Pesticide exposure among agricultural workers has been linked to certain cancers, DNA damage, oxidative stress, neurological disorders, and respiratory, metabolic, and thyroid effects.
SUMMARY: This review describes literature suggesting that agricultural workers exposed to synthetic pesticides are at an increased risk of certain cancers and neurological disorders. Recent research on respiratory effects is sparse, and more research is warranted regarding DNA damage, oxidative stress, metabolic outcomes, and thyroid effects. FULL TEXT
Thacker, 2020
Thacker, Paul D, “Transparency and Conflicts in Science: History of Influence, Scandal, and Denial,” Chapter 1 in Integrity, Transparency and Corruption in Healthcare & Research on Health, 2020,Volume I (pp. 3-26), Springer Nature Singapore.
ABSTRACT:
Corporate finances influence many areas of science, originating with tobacco companies which hired public relations firms to protect their profits from research on the harms of smoking. Despite a large body of studies finding that money biases research, scientists and academic organizations fail to embrace the peer-reviewed research on corporate influence. In many instances, they reject the science and try to rationalize behavior, leading a cycle of scandal, followed by reform, followed by later scandal. Because corporate influence is so pervasive and often denied, policymakers must understand this history as well as the research on financial conflicts of interest to protect the public. FULL TEXT
Ait-Bali et al., 2020
Ait-Bali, Y., Ba-M’hamed, S., Gambarotta, G., Sassoe-Pognetto, M., Giustetto, M., & Bennis, M.; “Pre- and postnatal exposure to glyphosate-based herbicide causes behavioral and cognitive impairments in adult mice: evidence of cortical ad hippocampal dysfunction;” Archives of Toxicology, 2020; DOI: 10.1007/s00204-020-02677-7.
ABSTRACT:
Glyphosate-based herbicides (GBH) are the most widely used pesticides worldwide. Despite considerable progress in describing the neurotoxic potential of GBH, the harmful effects on brain cytoarchitecture and behavior are still unclear. Here, we addressed the developmental impact of GBH by exposing female mice to 250 or 500 mg/kg doses of GBH during both pregnancy and lactation and then examined the downstream effects at the behavioral, neurochemical and molecular levels. We show that pre- and neonatal exposure to GBH impairs fertility and reproduction parameters as well as maternal behavior of exposed mothers. In offspring, GBH was responsible for a global delay in innate reflexes and a deficit in motor development. At the adult age, exposed animals showed a decrease of locomotor activity, sociability, learning and short- and long-term memory associated with alterations of cholinergic and dopaminergic systems. Furthermore, GBH-activated microglia and astrocytes, sign of neuroinflammation event in the medial prefrontal cortex and hippocampus. At the molecular level, a down-regulation of brain-derived neurotrophic factor (BDNF) expression and an up-regulation of tyrosine-related kinase receptor (TrkB), NR1 subunit of NMDA receptor as well as tumor necrosis factor alpha (TNFalpha) were found in the brain of GBH-exposed mice. The present work demonstrates that GBH induces numerous behavioral and cognitive abnormalities closely associated with significant histological, neurochemical and molecular impairments. It also raises fundamental concerns about the ability of current safety testing to assess risks of pesticide exposure during developmental periods of central nervous system. FULL TEXT
Vineis, 2019
Vineis, P.; “Public Health and Independent Risk Assessment;” American Journal of Public Health, 2019, 109(7), 978-980; DOI: 10.2105/AJPH.2019.305142.
Samet, 2019
Samet, J. M.; “Expert Review Under Attack: Glyphosate, Talc, and Cancer;” American Journal of Public Health, 2019, 109(7), 976-978; DOI: 10.2105/AJPH.2019.305131.
Morabia, 2019
Morabia, A.; “Fighting Independent Risk Assessment of Talc and Glyphosate: Whose Benefit Is It Anyway?;” American Journal of Public Health, 2019, 109(7), 955-956; DOI: 10.2105/AJPH.2019.305144.
Rodenberg, 2019
Rodenberg, H.; “Reliance, Not Responsibility: Relations Between Science and Industry;” American Journal of Public Health, 2019, 109(7), 980-981; DOI: 10.2105/AJPH.2019.305125.
Schaden et al., 2020
Schaden, Helmut Burtscher, Clausing, Peter, & Van Scharen, Hans. “Factsheet: Dangerous Confidence in ‘Good Laboratory Practices,'” February 11, 2020, Corporate Europe Observatory and PAN Germany.
SUMMARY:
Our authorisation system for chemicals is based on the principle that manufacturers must prove, by means of scientifc studies, that their products do not pose unacceptable risks to public health and the environment. It is therefore also the responsibility of manufacturers to commission certifed contract laboratories to carry out the toxicological studies necessary for the approval procedure. As a guarantee against manipulation and falsifcation of these “regulatory” studies, regulatory authorities worldwide rely on the certifed standard of “Good Laboratory Practice” (GLP). This standard provides for strict documentation requirements and regular internal and external controls. However, the current fraud scandal involving a German contract laboratory certifed according to GLP, shows that this trust is unlikely to be justifed. According to reports, GLP studies have been manipulated and falsifed there since 2005.
- Recent research now shows that LPT has also produced studies that were part of the study package for the EU-wide approval of glyphosate in December 2017: One in seven studies in this package, which was the basis to grant re-approval for glyphosate, came from LPT. These fndings are worrying in two ways: – On the one hand, there is the fundamental question of whether the risk assessments for medicines, pesticides and chemicals based on LPT studies can be trusted.
- Even more worrying is the general realisation that laboratories, despite the supposedly “tamper-proof” GLP standard, are apparently able to falsify studies over years and decades without being noticed by the control authorities.
The classifcation of glyphosate as “non-carcinogenic” and “not genotoxic“o is based, among other things, on the European authorities’ full confdence in the GLP system. In the EU assessment proces GLP studies were automatically classifed as reliable; This in stark contrast with the numerous “non-GLP studies” from university research, peer reviewed and published, most of which reported evidence of a genotoxic effect and an increased risk of lymphatic cancer in users of glyphosate, were disqualifed by the authorities as “unreliable“.
The LPT counterfeiting scandal reveals the failure of a regulatory system, that places the commissioning and preparation of studies in the hands of industry. At the same time, it confrms the urgency of a fundamental reform of this system for identifying the risks of chemicals, as called for by the European coalition “Citizens for Science in Pesticide Regulation” in October 2018. FULL TEXT
Wang et al., 2020
Wang, G. H., Berdy, B. M., Velasquez, O., Jovanovic, N., Alkhalifa, S., Minbiole, K. P. C., & Brucker, R. M.; “Changes in Microbiome Confer Multigenerational Host Resistance after Sub-toxic Pesticide Exposure;” Cell Host & Microbe, 2020; DOI: 10.1016/j.chom.2020.01.009.
ABSTRACT:
The gut is a first point of contact with ingested xenobiotics, where chemicals are metabolized directly by the host or microbiota. Atrazine is a widely used pesticide, but the role of the microbiome metabolism of this xenobiotic and the impact on host responses is unclear. We exposed successive generations of the wasp Nasonia vitripennis to subtoxic levels of atrazine and observed changes in the structure and function of the gut microbiome that conveyed atrazine resistance. This microbiome-mediated resistance was maternally inherited and increased over successive generations, while also heightening the rate of host genome selection. The rare gut bacteria Serratia marcescens and Pseudomonas protegens contributed to atrazine metabolism. Both of these bacteria contain genes that are linked to atrazine degradation and were sufficient to confer resistance in experimental wasp populations. Thus, pesticide exposure causes functional, inherited changes in the microbiome that should be considered when assessing xenobiotic exposure and as potential countermeasures to toxicity. FULL TEXT