Mapping commercial practices of the pesticide industry to shape science and policymaking: a scoping review

Abstract

There is a growing body of evidence for how health harming industries (HHIs) engage in similar practices to influence science and policymaking. However, limited attention has been paid to the pesticide industry within the commercial determinants of health (CDOH) field. We conducted a scoping review to map practices adopted by the pesticide industry to influence science and policymaking and to assess the breadth and focus of the associated literature. We included 31 documents and categorized the extracted data using a typology of commercial practices. The documents described how major pesticide companies, and their trade bodies, have acted to influence science and maintain favourable regulatory environments while undermining the credibility of researchers and agencies that publish findings threatening to their commercial interests. A large proportion of the literature consists of historical analyses, narrative reviews, commentaries/perspective pieces, and investigative reports published in the grey literature, predominantly informed by analysis of internal industry documents and freedom of information requests. Most studies focus on high-income settings. There were a limited number of primary peer-reviewed empirical studies that explicitly aimed to study the practices of the pesticide industry from a CDOH perspective. However, our findings show that major pesticide companies adopt political and scientific practices highly similar to other HHIs. The review shows a critical need for research on the pesticide industry’s current practices in low- and middle-income countries where the negative impacts of its activities on health and the environment are likely to be more marked.

INTRODUCTION

There is growing evidence that commercial actors whose products and means of production are potentially harmful to health engage in similar practices to influence policy and science in ways that undermine population health (Brownell and Warner 2009; White and Bero 2010; Proctor 2012; Knai et al. 2021; Hill et al. 2022; Gilmore et al. 2023). The study of these practices forms part of a wider field of research known as the commercial determinants of health (CDOH) (Maani et al. 2022; Gilmore et al. 2023). These are defined as the ‘systems, practices, and pathways through which commercial actors drive health and equity’ (Gilmore et al. 2023). This field of research has, to date, predominantly focused on the practices of those health harming industries (HHIs) understood to be the main drivers of non-communicable diseases (e.g. tobacco, alcohol, ultra-processed food and drinks, and fossil fuels) and related sectors (e.g. manufacturers of infant formula) (Gilmore et al. 2023). Yet, there is a growing need to extend analysis to incorporate the practices of other commercial actors of significance for public health, with a notable example being the pesticide industry.

Since the 1990s, frequent mergers and acquisitions have led to the development of large transnational pesticide corporations that dominate the global market (Clapp 2021). Four companies collectively account for 84% of total market share (Friends of the Earth). As of 2019, this market was valued at approximately $84.5 billion (The Business Research Company 2020). The principal players are BASF (originally founded as Badische Anilin- & Sodafabrik), Bayer-Monsanto (formerly separately Bayer and Monsanto, with Bayer acquiring Monsanto in 2018), Corteva (formerly DowDuPont), and Syngenta. These corporations exert significant influence over the entire supply chain, from research and development to production, sales, and distribution (Terwindt et al. 2018). This trend in industry consolidation resembles that of other HHIs. For example, 80% of the global tobacco market is held by five firms (Vital Strategies and Tobacconomics 2024), and 67% of the global beer market is owned by 10 corporations (Jernigan and Ross 2020).

Consistent with other HHIs, major commercial actors from within the pesticide industry (i.e. pesticide producers, suppliers, retailers, and their trade groups) have shifted their focus to the Global South, as regulations prohibiting the use of many highly hazardous pesticides (HHPs) have been adopted in high-income settings (Tostado and Bollmohr 2022). The World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO) define HHPs as:

pesticides that are acknowledged to present particularly high levels of acute or chronic hazards to health or environment according to internationally accepted classification systems such as WHO or Global Harmonized System (GHS) or their listing in relevant binding international agreements or conventions. In addition, pesticides that appear to cause severe or irreversible harm to health or the environment under conditions of use in a country may be considered to be and treated as highly hazardous (UN Environment Programme 2024).

Pesticides and the regulation of their production and use are important from a public health perspective. Pesticides are used as part of vector-borne disease control programmes and are used extensively in many agricultural systems across the world (Food and Agriculture Organization and World Health Organization 2014). The greatest burden of the negative impacts of pesticide exposure is experienced by those living in low- and middle-income countries (LMICs) where pesticide legislation is often weak or absent (Pesticide Action Network UK 2020; van den Berg et al. 2020), and capacities to protect against occupational and other exposure to HHPs are often lacking (Food and Agriculture Organization and World Health Organization 2014; van den Berg et al. 2020). Most fatal intentional pesticide poisonings, the majority of which are associated with HHPs, occur in LMICs (Mew et al. 2017). Many HHPs (such as atrazine, glyphosate, and paraquat, as per the definition adopted by the Pesticide Action Network) produced in high-income countries (HICs) are banned for use in such settings because of the risks posed to health and the environment but continue to be exported to LMICs (Public Eye 2019). Exposure to pesticides through environmental pollution has been associated with adverse health impacts, including neurological diseases and cancers, and detrimental effects on fertility or pregnancy (Roberts and Reigart 2013). Globally, pesticides remain an important source of chemical pollution impacting the health of communities and the environments on which they depend (WHO 2016; Fuller et al. 2022).

However, despite its comparable size, influence, and significance for public health and environmental sustainability, the commercial practices of the pesticide industry have received limited attention within the CDOH field (Legg et al. 2021; Gilmore et al. 2023), and there has been no previous overview of the relevant literature from a CDOH perspective to inform the development of research, practice, and policy. To fill this gap and explore areas for future research, we conducted a scoping review to map the literature that provides accounts of scientific and political practices adopted by the pesticide industry. We also categorized the types of evidence presented for these practices to identify the knowledge and theoretical gaps in studying the pesticide industry as a CDOH.

METHODS

We employed a scoping review methodology, given the disparate nature of the literature on the pesticide industry and its practices, and the limited amount of prior work to review this literature from a CDOH perspective. We conducted the review in accordance with the Joana Briggs Institute methodology (Peters et al., 2021) to describe the breadth and focus of the existing accounts. We focused on the political and scientific activities of the pesticide industry, capturing a range of document types and study designs. Our scoping review drew on an emerging typology of commercial practices described in the CDOH literature (Gilmore et al. 2023), which provides an important analytical tool for the identification and characterization of how commercial actors seek to influence health, policy, and science and the consequences.

Search strategy

We conducted a staged search process to identify relevant documents. We undertook a Google search with broad search terms (main company names and terms relating to strategies or tactics) to identify relevant articles and to develop a set of keywords for a full search strategy. We developed our search strategy with support from a subject librarian at the University of Edinburgh and implemented and adapted it for Scopus, Medline, Web of Science, CAB Abstracts, Policy Commons, and Global Health (CABI) (Supplementary File 1). The search terms were structured to the PCC approach (Pollock et al. 2023): population (pesticide industry terms or specific companies), concept (terms relating to industry strategies or tactics), and context (science or policymaking).

Scoping searches in agriculture databases (AgEcon, AGRIS, agriRxiv, Agricola) did not yield any results and these databases were therefore not pursued further. We conducted additional searches in Google to identify relevant reports in the grey literature using similar search terms. We screened reference lists of included articles for additional studies. We also consulted experts in the fields of pesticide poisoning, CDOH, environmental health, and agriculture to identify additional relevant articles and books that present analyses of internal industry documents originating from the pesticide industry. We conducted database searches in May 2022 and updated them in August 2024. These searches were supplemented by other documents known to the study team.

Inclusion and exclusion criteria

Empirical studies, commentary/perspective pieces, reviews, books, and reports published in the grey literature were included if they provided accounts of industry practices. We applied no limit to year of publication or language. While our focus was on pesticides, documents that reported on practices by Monsanto in relation to regulation of genetically modified (GM) products were included since these products were intended to be used in conjunction with Monsanto’s main pesticide product, Roundup (glyphosate) (Gillam 2017, 2021). We excluded studies that did not report on the pesticide industry or provide a detailed description of the industry’s practices directed at influencing science, policymaking, or regulation. We excluded documents that described pesticide industry practices that were out of scope for the review (e.g. labour and employment rights).

Document selection

We collated all identified documents and uploaded these to Covidence (2023) for de-duplication. L.S. and M.v.S. independently screened titles and abstracts to identify eligible articles for inclusion. Potentially relevant documents were reviewed in full by L.S. and M.v.S. against the inclusion criteria. Any discrepancies were resolved through discussion to reach a consensus and reasons for exclusion were recorded. Studies not written in English (n = 4) were reviewed by two researchers proficient in either Spanish or Portuguese in the screening and data extraction phase (one document was subsequently included in the review).

Data extraction and synthesis

We completed a data extraction form summarizing basic characteristics (e.g. document type, data source for the document, and type of practice) for all included documents (Supplementary File 2). We did not formally evaluate the level or quality of included documents, consistent with the aims of a scoping review and previous scoping reviews (Legg et al. 2021). We categorized each document by the type of evidence provided for commercial practices and their impacts (i.e. whether it was descriptive or a theoretically informed empirical analysis). Data related to these practices were then extracted and grouped according to a typology of commercial practices developed by Gilmore et al. (2023). This typology describes seven commercial practices: political practices, scientific practices, marketing practices, supply chain and waste practices, labour and employment practices, financial practices, and reputational management practices (Gilmore et al. 2023). Our review focused on mapping accounts of political and scientific practices to provide initial insights into how the pesticide industry functions as a CDOH and given the importance of these practices from a public health perspective and their well-documented use by other HHIs. Focusing on a subset of practices also ensured that our review was manageable and that a comprehensive mapping of the included practices and associated literature could be performed. We also extracted evidence for reputational management practices within the included documents given the overlap of these practices with all other practices in the typology (Gilmore et al. 2023). The typology was used to inform the classification, grouping and presentation of the practices described in the included documents while also allowing us to identify theoretical and knowledge gaps in the literature.

RESULTS

We present the search results and screening process in a Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for scoping review (PRISMA-ScR) flow diagram (Fig. 1). We screened 826 titles and abstracts, of which 736 were identified as irrelevant and therefore excluded. The remaining 90 full texts were screened for inclusion, of which 22 documents from database searches and nine documents identified through other sources met the inclusion criteria. In this article, we refer to all included sources (N = 31) collectively as ‘documents’ to reflect that a range of study or article types were identified by the scoping review.

Characteristics of documents

We included commentaries/perspective pieces (n = 9), empirical studies (n = 8), narrative reviews (n = 6), grey literature reports (n = 4), books (n = 3), and systematic review (n = 1). An overview of each included document and the data sources they draw on is provided in Table 1. Most of the documents (n = 20) described events within HICs, four in upper-middle-income countries (Brazil, Argentina, and Costa Rica), and two covering LMICs more broadly. The remaining five documents were more general, with most of the information applying to HIC contexts. Most documents described the practices adopted by Monsanto and related events (n = 15), while others focused on multiple companies (n = 4), Bayer (n = 2), and what was then Dow Chemical [Dow separated from DowDuPont in 2019, which then became Corteva Agriscience (Dupont 2018; Dow 2019)], Shell Oil (n = 1), and Imperial Chemical Industries Agrochemicals (predecessor company to Zeneca and Syngenta) (n = 1). One systematic review and meta-analysis focused on the pesticide atrazine (of which Syngenta is the primary producer) but did not explicitly name specific companies. This study aimed to analyse the relationship between study sponsorship, risk of bias, and research outcomes in non-human atrazine exposure studies (Bero et al. 2016).

In the following sections, we describe the scientific, political, and reputational practices identified in the included documents while recognizing their often inter-related and overlapping nature and effects. Additional examples are described in Table 2. The three included books (Gillam 2017, 2021; Séralini 2021) presented many detailed and thoroughly researched examples across the identified practices and expanded on some of the events described in other included documents, but additional scientific and political practices were not identified. Therefore, the below examples are drawn mostly from sources other than these books while recognizing the depth and detail they provide in addition to other published sources.

Political practices: protecting the unhindered use of pesticides

Gilmore et al. (2023) define political practices as ‘practices to secure preferential treatment or that prevent, shape, circumvent, or undermine public policies (or a combination of the above) in ways that further corporate interests’. Included documents contained accounts of political practices adopted by major pesticide companies directed at preventing the reclassification of products and strengthening of regulatory restrictions. These included well-financed lobbying of legislators and regulatory agencies and the movement of individuals between roles as regulators or policymakers to employees of, or lobbyists for, industries affected by legislation, known as the ‘revolving door’ phenomenon.

Lobbying

Lobbying of policymakers and regulators was a key practice described within included documents. Evidence was provided by some documents for the substantial financial resources expended by the pesticide industry to lobby policymakers, both in the USA (Clapp 2021) and in the European Union (EU) (Corporate Europe Observatory 2022). Other accounts provided detailed descriptions indicating that in Brazil, a major exporter of agricultural products, the agribusiness, including pesticide companies, had access to policymakers, which allowed for lobbying on specific regulatory matters (De Olho Nos Ruralistas 2022). A report by De Olho Nos Ruralistas (2022) reported that between 2019 and 2022, a total of 160 meetings were granted to an agribusiness think tank, compared with two with farmer organizations. This indicates that industry was afforded substantially more opportunity than other stakeholders, like those representing farmers, to lobby for regulations that favoured their interests (De Olho Nos Ruralistas 2022). Another example was Malkan et al. (2022), a US Right to Know report based on analysis of discovery documents, data obtained through freedom of information (FOI) laws and investigative journalist articles. They provided an account of Monsanto’s effort to influence the US Environmental Protection Agency (EPA) review of glyphosate’s classification as a carcinogen. It seems that these practices were adopted in response to potential regulatory threats in the USA, arising from a 2015 ruling by the WHO’s International Agency for Research on Cancer (IARC) that glyphosate, one of Monsanto’s most profitable products, is a probable human carcinogen. According to the report, Monsanto representatives engaged with the EPA staff member who oversaw the agency’s assessment of glyphosate as a carcinogen and authored a report concluding glyphosate is not carcinogenic (Malkan et al. 2022).

Revolving doors and relationships between industry and regulatory agencies

The existence of a ‘revolving door’ between major pesticide producers and regulatory agencies was described in several documents, including reviews (Pelaez and Sbicca 2003), analyses from the peer-reviewed and grey literature based on internal industry documents released during the discovery process of legal proceedings, corporate archives, and access to information requests (Jones and Lubinski 2014; Krimsky and Gillam 2018; De Olho Nos Ruralistas 2022; Malkan et al. 2022), and commentaries (Robinson et al. 2013; Vainio 2020; Glenna and Bruce 2021; Rohr 2021). De Olho Nos Ruralista’s (2022) analysis of meeting records and data obtained through access to information requests found that Bayer’s head of public affairs had worked within the Brazilian federal government before acting as a lobbyist, participating in meetings with the Ministry of Agriculture, Livestock, and Food Supply. Similarly, Malkan et al. (2022) described how within the US context a member of staff from the EPA left the agency to work for a public relations firm who provided services for Monsanto, only to return to working for the EPA during the Trump Administration. Another account reported that staff from consulting firms working with Syngenta also held roles within an EPA advisory board (Rohr 2021). The International Life Sciences Institute (ILSI), an organization formed by a former senior vice president at Coca-Cola, with an established relationship with Monsanto, served as chair for FAO/WHO meetings on the carcinogen classification of glyphosate. Additionally, one document described how a member of the management board for the European Food Safety Authority (EFSA) became an employee within ILSI, then subsequently moved back to EFSA (Robinson et al. 2013).

Scientific practices: sowing seeds of doubt about the harm of pesticides

Scientific practices are defined as those ‘involving the production and use of science to alter products or otherwise secure favourable outcomes (or both) for the industry’ (Gilmore et al. 2023). Several scientific practices were described in the documents, including concealing of industry involvement in the scientific process, funding of industry-favourable research, attacking of threatening research and independent scientists, and framing of research findings in ways beneficial to industry.

Undisclosed conflicts of interests and ghost-writing

Some of the included documents specifically described examples of corporate involvement in the practice of ‘ghost-writing’ papers (Krimsky and Gillam 2018; McHenry 2018; Glenna and Bruce 2021), in particular Monsanto’s efforts to discredit IARC’s assessment of glyphosate as a probable carcinogen (Vainio 2020). In their analysis of internal industry documents, Glenna and Bruce, (2021) described how Monsanto’s employees were contributing to the development of articles that downplayed the carcinogenicity of glyphosate but failed to disclose this involvement. Gillam (2017) presented evidence from documents released under FOI requests in which Monsanto directly solicited a group of researchers to write scientific articles promoting the safety of GM crops. However, the articles produced through this arrangement did not acknowledge Monsanto’s role in influencing their content. A report produced by Corporate Europe Observatory on the EU Farm to Fork Strategy (Corporate Europe Observatory 2022) described how a university issued a press release about an impact study critiquing the Farm to ForkStrategy (which aimed to reduce pesticide use), claiming it would lower agricultural yields. The press release however failed to disclose that the study had been funded by CropLife International, a trade association made up of major agrochemical companies. Similarly, Syngenta acted to influence the debate around the Farm to Fork Strategy by sponsoring an opinion piece critiquing the pesticide use target proposed by the European Commission (EC). The study cited by the authors of the opinion piece to defend their criticism was not acknowledged as being industry funded (Corporate Europe Observatory 2022).

Attacking or influencing individual scientists and their research

Some of the included documents described how both Monsanto and Syngenta sought to attack and undermine the research and reputation of scientists whose work threatened their business interests. Séralini and colleagues provided the most detailed examples of Monsanto’s active engagement in disputing research that went against their business interests (Séralini et al. 2014; Séralini and Douzelet 2021). The authors described how Séralini’s own research was actively attacked by Monsanto and resulted in the retraction of a study on the effects of glyphosate despite no evidence of research misconduct. Séralini et al. documented the actors and processes that had contributed to the paper being retracted (Séralini et al. 2014; Séralini and Douzelet 2021). For example, Monsanto’s involvement in the process was actively concealed presumably to avoid undermining the apparent legitimacy of the complaints about Seralini’s work (Krimsky and Gillam 2018). Similar accounts were presented of Syngenta’s attempts to undermine research conducted by Dr Tyorne Hayes, which suggested that atrazine had detrimental reproductive effects on amphibians even below levels permitted in drinking water (Rohr 2021).

Producing evidence to influence regulatory action

A key scientific practice described in several of the included documents was the industry’s attempts to produce an industry-favourable evidence base that could be used to help it resist regulatory action. There were several such examples, including direct funding of articles that were critical of IARC and that questioned their decision to categorize glyphosate as probably carcinogenic to humans (Infante et al. 2018). Monsanto also produced studies that were later included in a commissioned study to assess the cancer risk of glyphosate by the European Parliament (Malkan et al. 2022). The impact of industry funding was also demonstrated by the selective inclusion of evidence that downplayed risks in industry-funded reports (Folguera 2021), as well as more often concluding that there is ‘inconclusive’ evidence of risk (Folguera 2021). Bero et al. (2016) studied the impact of industry funding on research findings in a systematic review of animal studies assessing the effects of atrazine exposure. Their study found that harmful effects were reported in 50% of non-industry-funded studies compared to only 18% of industry-funded studies. Industry-funded studies were also less likely to report statistically significant harmful effects (9% vs. 33% of studies funded by independent sources). Notably, 10 of the 51 studies did not disclose funding (Bero et al. 2016). The evidence base was also biased by avoiding the use of established toxicological methods to test for health harms from pesticide exposure. This was clear from a study examining pesticide exposure, where the producer of dibromochloropropane (DBCP), Shell, suppressed reports of sterility in USA and Costa Rican workers and their scientists admitted that correct toxicological testing had not been used. The suppression and inadequate testing allowed Shell to continue to support the use of DBCP by the Standard Fruit company in Costa Rica for over a decade (Thrupp 1991). Conversely, Eddleston provided evidence for how Imperial Chemical Industries Agrochemicals, and its successor company Syngenta, promoted the use of formulations of paraquat supplemented with the emetic PP796 to improve safety despite internal understanding of the limited evidence in support of this claim and the weaknesses of its own internal studies.

In another example, Corporate Europe Observatory (2022) analysed EC documents acquired through FOI access requests, personal communications, submissions to consultations, and EC lobby/stakeholder events related to the EU Farm to Fork Strategy. They described how it was evident that the industry had commissioned impact assessments that aimed to undermine the Farm to Fork Strategy and lobbied the EC to undertake its own impact assessment of the strategy. One of the commissioned studies was reported as having clear influence from CropLife.

Reputational management practices: protecting the ‘feeding the world’ narrative

Alongside the above-documented political and scientific practices, pesticide companies and their trade bodies adopted several reputational management practices. These served to maintain their legitimacy as policy actors, as authoritative voices on the safety of their products, and to assert that the industry and its products are helping to meet the agricultural needs of the world.

Influencing regulatory bodies and creating narratives about working with stakeholders

In their efforts to influence regulatory systems, commercial actors within the pesticide industry and their trade associations sought to frame the industry as part of the solution and to promote forms of partnership working. These practices included disseminating industry-favourable framings of study results, constructing narratives that present the industry as working collaboratively to enable progress (Corporate Europe Observatory 2022), and positioning themselves as having common goals with FAO and WHO (Public Eye 2019). A report by Public Eye, an NGO that focuses on investigating and exposing human rights violations perpetuated by Swiss-based companies, described how CropLife rhetorically aligned their goal with that of WHO and FAO and claimed to be working alongside these agencies to make less toxic pesticides available on the market (Public Eye 2019). However, this obscures the ongoing export of HHPs, such as paraquat, primarily to LMICs (Public Eye 2019). One element of these practices involved building support among farmers, which enabled the industry to incorporate the issue of pesticide use into broader issues of global warming and food insecurity (Goldberg and Vandenberg 2019).

Burnishing the corporate image

Included documents described how different companies have created narratives about their products and associated harms directed at both public audiences and those within their own organizations. Many examples related to Monsanto, including partnering and funding public relations activities to specifically discredit IARC and cast doubt on their decision to classify glyphosate as carcinogenic to humans (Vainio 2020; International Food Information Council 2024). In another context, Glover (Glover 2010) described the emergence of Monsanto’s framing of GM crops as ‘pro-poor’ and environmentally sustainable. In Germany, Jones and Lubinski (2014) described how Monsanto actively constructed and embedded a narrative about their role in supporting global food production when facing backlash from consumers in Europe against the use of GMOs. Other examples include Bayer, who in the 1970s worked on their public image to ensure they were seen as acting as a responsible company and engaged with school children to host an exhibition related to environmental protection. Internal documents discussing the thinking behind these activities showed that ‘Bayer managers argued that it was necessary to engage in more active marketing efforts to counter the “industry hostility”’ (Jones and Lubinski 2014, p. 639).

Other studies of Monsanto’s business activities focused on their approach to biotechnology. Based on discourse analysis of Monsanto documents, Lamphere and East (2017) described how in the mid- to late 1990s, the company positioned itself as developing new technologies to meet the needs of a world in which food insecurity was framed as a key issue. This framing was used to legitimize both their restructuring of the organization and their technological developments (which included Roundup, their main pesticide product, and recombinant bovine growth hormone). In the early 2000s, Monsanto’s corporate messaging reinforced these framings that had been constructed in the previous decade. Monsanto adopted what they called a New Monsanto Pledge, which positioned the company as contributing to sustainability. The authors, however, argued that the language used did not necessarily indicate a pledge for action but reflected Monsanto’s narrowly constructed framing of the issue to normalize and legitimize the use of technology as the only option to achieve sustainability. Moreover, Monsanto presented itself as part of the solution and aligned its framing with wider sustainability and human rights policy agendas (Lamphere and East 2017).

DISCUSSION

This scoping review provides a mapping of the literature describing the commercial practices of major pesticide companies to influence science and policymaking. Collectively, the included documents represent a valuable body of evidence for how the pesticide industry has acted to influence understanding of the harms associated with its products and to block, delay, or weaken attempts to restrict the (re)licensing and use of pesticides. This has been achieved through well-characterized and synergistic practices that function to subvert scientific, policymaking, and regulatory processes while maintaining the industry’s social licence to practice in the interest of maximizing commercial gain but at the expense of public health. The activities described paint a picture of an industry that has engaged in a range of practices, across time and place, to produce an industry-favourable evidence base, including the direct of funding research and impact assessments, ghost-writing of manuscripts, interfering in the peer review process, and actively discrediting the research of academics and organizations such as IARC whose activities threaten industry interests.

Beyond influencing the production of knowledge, the industry has engaged in shaping the use of evidence by policymakers and regulatory agencies and other institutions like the EC and their decision-making functions, including withholding of internal evidence for the harm associated with their products. The industry and its representative trade bodies have acted to establish themselves as legitimate partners in the production of evidence and policy and as playing a positive role in ensuring safe use of pesticides and the creation of sustainable agricultural systems. Coupled with the existence of revolving doors between the industry and regulatory bodies in multiple contexts, and the embedding of industry-favourable norms and practices related to the assessment and use of pesticides, these practices have helped in establishing policy and regulatory systems that are highly amenable to the interests of the pesticide industry.

These documented practices are highly consistent with those of other HHIs, such as the tobacco, alcohol, unhealthy food and beverage, fossil fuels, lead, and asbestos industries, which have cast doubt about the harms of their products and disarmed attempts to restrict their commercial activities: from the distorting and misuse of science to the influencing of the academic process, policymakers, regulatory bodies, and public perceptions and understanding (Markowitz and Rosner 2002; Tweedale and McCulloch 2008; Knai et al. 2018; Lauber et al. 2021; Legg et al. 2021; Carvalho et al. 2022; Gilmore et al. 2023; Ulucanlar et al. 2023). This gives further support to previous scholars who have called into question the tendency to treat commercial actors differently because they produce products with divergent implications for health and the environment (Hawkins et al. 2018; Knai et al. 2021; Hill et al. 2022). It signals the need for a comprehensive conceptualization of how commercial practices and products impact health beyond a narrow focus on those industries that manufacture particular consumer products associated with non-communicable diseases. The findings of this review make a clear case for the CDOH community to afford the pesticide industry the same level of attention that has been traditionally directed at other HHIs. Indeed, more recent studies included in our review, such as Bacon et al. (2023), suggest a growing recognition among scholars of the need to apply a CDOH lens to the pesticide industry including to its engagement with policymakers, regulatory agencies, and researchers.

Most accounts of the pesticide industry’s practices were provided by commentaries and comprehensive investigative reports published in the grey literature, as well as a limited number of empirical, theoretically informed studies explicitly designed to describe and critique these practices as structural determinants of health and equity. Investigative journalists and advocacy organizations have been instrumental in exposing and describing the practices of the industry. The state and focus of the literature reflect the availability of internal industry documents released during the discovery process of legal proceedings in the USA, which have proved an invaluable source of evidence for how this industry operates to shape science and policy in ways conducive to its interests. Much of the literature therefore describes events and commercial practices related to Monsanto and Syngenta as main producers of the pesticide glyphosate-based Roundup and atrazine, respectively, which have been at the centre of much of this ligation.

As a scoping review of an under-researched CDOH, we adopted a narrow focus on the practices employed by the pesticide industry to shape science and policymaking and the related practice of reputational management. While it was limited to these practices and did not involve a full systematic review of the literature or critical interpretive analysis of the extracted data, by including a range of document types it provides informative insights into the set of practices used by the pesticide industry to shape science and policymaking and the state of the literature documenting these. Use of a published typology enabled us to map and describe these practices from a CDOH perspective; however, challenges remain with regards to allocating some practices to specific categories or type. This reflects the considerable overlap between the scientific, political, and reputational management practices adopted by commercial actors and the functions they serve (Gilmore et al. 2023; Ulucanlar et al. 2023).

Future research

Our scoping review helps to illuminate topics and contexts that require analysis from a CDOH perspective. For example, HHPs are recognized as common means for suicide (Mew et al. 2017), and restricting access to HHPs is a cost-effective intervention to prevent suicide by pesticide poisoning (Lange et al., 2024). Simultaneously, the industry has acted to promote alternative approaches favourable to their commercial interests, such as ‘safe storage’ practices (Konradsen et al. 2007). Yet, we did not identify a body of literature examining the pesticide industry’s attempts to shape suicide prevention research and policy agendas of governmental and non-governmental organizations. Similarly, we did not identify literature analysing the industry’s activities in the context of other policy agendas of critical importance to both health and the industry’s commercial interests, such as the proceedings of the FAO and WHO Joint Meeting on Pesticide Management (Food and Agriculture Organization and World Health Organization, 2024; World Health Organization 2024) or the implementation and review of the Rotterdam Convention (Secretariat of the Rotterdam Convention 2024), an international treaty that aims to govern international trade, and environmentally sound use of, particular hazardous chemicals. Future research could focus on building greater understanding of how the pesticide industry engages with such bodies and systems of policymaking as well as other developments, such as synergies between the policy practices of the pesticide industry and the commercial priorities of other industries of relevance to health, such as major food producers and the growing cannabis industry (Subritzky et al. 2017; Orenstein and Glantz 2020). More attention should also be directed at studying the industry’s ongoing efforts to shape understanding of and policy responses to emerging effects associated with exposure to their products, notably the potential risk of Parkinson’s disease and threats posed to bees and other pollinators. Additional studies are needed to map and review the literature that describes and analyses the pesticide industries’ marketing, supply chain and waste, labour and employment, and financial practices, which were beyond the focus of this scoping review.

Most importantly, the majority of the studies identified by our review described industry activities in HICs. Those who are at greatest risk from the activities of the pesticide industry are under-represented in the literature included in this review and few studies consider the industry as a driver of inequities. Much more focus is needed on the practices adopted by the pesticides industry in LMICs that are most affected by, and dependent on, the industry’s products and practices. This finding is consistent with other’s assessment of the CDOH evidence base and the need for more analysis of industry practices in LMIC settings (Abdalla et al., 2022). This dearth can be considered particularly significant in the context of pesticides given the distinctive combination of an inequitable distribution of global health impacts, striking divergence in regulation and greater exposure to much more hazardous products, banned for use in HICs but manufactured and exported to countries in the Global South.

Implications

While the scoping review reveals avenues for future research, the findings have clear implications for policymakers and regulatory agencies, as well as the academic, public health, and advocacy communities. The totality of evidence presented here reinforces previous calls for transformational reforms to address industry influence of policymaking and the functioning of regulatory agencies to protect such processes from undue industry influence and maintain their independence, including the establishment of robust and effective governance systems for engaging with industry (Baur et al. 2019; Moynihan et al. 2019; Mialon et al. 2020; Reed et al. 2021). As Reed et al. (2021) discuss, major changes are urgently needed to shift the outsized influence that commercial actors have on health policymaking and governments should be held to account for failing to counter harmful commercial practices. At a minimum, greater transparency of the lobbying practices of the pesticide industry could be facilitated through the establishment of comprehensive lobbying registers. However, such a measure alone will be insufficient and wider system and governance changes are needed to address the power imbalances that exist in the policymaking space between the ability of those who are harmed by pesticide exposure and those who profit from weak regulation and ubiquitous use of pesticides.

Transformational changes are needed to ensure the independent functioning of agencies that regulate pesticides and other forms of chemical hazards and pollution to ensure the protection of public health, particularly among vulnerable populations. Woodruff et al. (2023) have proposed five overarching principles and scientific recommendations to guide the use of science across all areas of chemical exposure, hazard, and risk assessment to prevent and minimize public health impacts. These include measures to shift away from the use of industry-favourable assumptions and logics, including the assumption that there exists a ‘safe’ or ‘no-risk’ level of chemical exposure in the general population, shifting the financial burden of data generation for any given chemical onto the producers that benefit from their (re)introduction onto the market, and mandating that hazard and risk assessments evaluate and account for financial conflicts of interest (COI) in the evidence base. Similarly, the findings presented above also re-affirm the need for much stronger measures to protect research from industry influence and maintain academic independence (Baur et al. 2019). For example, Baur et al. (2019) put forward key principles for safeguarding the integrity of research in occupational and environmental global public health. The first of these emphasizes the pressing need to strengthen COI declaration policies to cover financial and other forms of relationships with relevant industries, and penalties for inaccurate disclosures, to protect peer review journals, peer review panels, and government entities (a necessary but insufficient measure). The second calls for maintaining high ethical standards within academic and other related institutions, and the third for governments to ensure the availability of independent funding sources for research. The fourth principle describes the importance of protecting the decision-making process from COIs and ensuring that research evidence used to inform policy is evaluated against criteria set by an independent scientific community, and not the industry being assessed. Finally, measures must be taken globally to restore dignity in academic publishing (Baur et al. 2019). In seeking to address such concerns, there is clear scope to draw on experiences of developing and implementing norms, rules, and policy tools to effectively minimize tobacco industry interference in public health policy (Ralston et al. 2021, 2022), to manage conflict of interest in nutrition policy (Ralston et al. 2021), and emergent tools to support more effective and accountable engagement with private sector actors (WHO 2024).

CONCLUSIONS

The pesticide industry is made up of major global corporations whose products and practices have considerable impacts on human health and the environment. However, there is a clear need for further research on the practices of the pesticide industry, particularly in relation to the industry’s attempts to shape policy developments in LMICs and at the international level across a range of issues, and to assess the implications for health and the environment. This scoping review provides an initial mapping of the literature on some of the industry’s practices that can serve as a foundation for future research agendas to study the pesticide industry from a CDOH perspective. The importance of adopting such a perspective is becoming ever apparent given the pressing need to identify effective ways to achieve global health, equity, and environmental sustainability goals.

Acknowledgements

The authors would like to thank Donna Watson, subject librarian at University of Edinburgh, for support with developing the search strategy.

Funding

L.S. receives salary support from the Centre for Pesticide Suicide Prevention (CPSP), which is funded by a grant from Open Philanthropy, at the recommendation of GiveWell, and has grant funding from the Carnegie Trust. L.S. has previously had grant funding from the Institute for Alcohol Studies. M.Pea. has received funding from the American Foundation for Suicide Prevention (AFSP) on a Young Investigator grant (2018) and salary support on an Investigator Grant, and the Centre for Pesticide Suicide Prevention (CPSP) has provided salary support. D.K. has received funding from AFSP and CPSP for research related to suicide and self-harm. M.v.S. was funded by the National Institute for Health Research (NIHR) Doctoral Fellowship (NIHR3000156) and her research was also partially supported by the NIHR Applied Research Collaboration North Thames. The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care. M.v.S., M.P., and J.C. have funding through and are co-investigators, respectively, in the SPECTRUM consortium, which is funded by the UK Prevention Research Partnership (UKPRP), a consortium of UK funders [UKRI Research Councils: Medical Research Council (MRC), Engineering and Physical Sciences Research Council (EPSRC), Economic and Social Research Council (ESRC) and Natural Environment Research Council (NERC); Charities: British Heart Foundation, Cancer Research UK, Wellcome and The Health Foundation; Government: Scottish Government Chief Scientist Office, Health and Care Research Wales, National Institute of Health Research (NIHR) and Public Health Agency (NI)]. M.P. has grant funding from the National Institute for Health Research (NIHR) ‘Three Schools’ Mental Health Programme.

Conflict of interest

M.Pea. is a member of the International Association for Suicide Prevention (IASP) and a Co-Chair of the Special Interest Group Prevention of Intentional Pesticide Poisoning. D.G. has been a co-applicant on AFSP funding awards and grants. D.G. was an (unpaid) expert adviser to WHO’s First Consultation on Best Practices on Community Action for safer access to pesticides (Geneva, 2006). He was an (unpaid) expert adviser to WHO’s Consultation on cost-effectiveness of suicide prevention interventions, including pesticide regulation (Geneva, 2019). D.G. drafted and provided technical assistance for the development and publication of a WHO resource tool for ‘Suicide prevention: a resource guide for pesticide registrars and regulators’ (WHO, May–June 2019) and received a small grant for this work. D.G. was a member of the scientific advisory group for a Syngenta-funded study to assess the toxicity of a new paraquat formulation (2002–06); a member of the scientific advisory group for a pesticide storage project funded by Syngenta (2005–07); and chaired the data monitoring and ethics committee (DMEC) for a Syngenta-funded trial of the medical management of paraquat poisoning (2007–10). D.G. received travel costs to attend research and DMEC meetings of the Syngenta funding studies, but no other fees. D.G. was Former Samaritans trustee (2015–18) and a member of Samaritans Policy and Research Committee (2015–21), Movember’s Global Advisory Committee (2019–22), Department of Health (England) National Suicide Prevention Strategy Advisory Group, and IASP (all unpaid roles). M.v.S. is on the Editorial board at Health Promotion International. M.v.S. was a guest editor on the CDoH special issue published by Health Promotion International. M.P. is on the Advisory Board of Health Promotion International. None of the authors were involved in the review process or in any decision-making on the manuscript. R.B. and M.E. have nothing to declare.

Data availability

All data used in this study are in the public domain

References