A Social Survey to Capture the Public Awareness and Perception About Chemicals Under Ireland’s Human Biomonitoring Feasibility Study

Abstract

As chemical exposures are increasingly emphasised as public health concerns, understanding how people perceive chemical risks is vital for shaping responsive and inclusive human biomonitoring (HBM) programmes. Public awareness not only influences individual behaviours but can also inform national policy priorities and scientific focus. This study reports findings from the Human Biomonitoring for Ireland (HBM4IRE) feasibility study, which conducted a social survey adapted from the HBM4EU framework. The survey assessed awareness and perceived harmfulness of 24 chemical groups among 218 Irish residents, distinguishing between experts (involved in chemical management) and non-experts. Lead, arsenic, mercury, pesticides, tobacco alkaloids, volatile organic compounds (VOCs), solvents, cadmium, polycyclic aromatic hydrocarbons (PAHs), and persistent organic pollutants (POPs) received the highest perceived harmfulness scores. Non-experts reported lower perceived harmfulness for substances such as phthalates, parabens, and Per- and polyfluoroalkyl substances (PFASs), indicating significant awareness gaps. These findings demonstrate convergence between public and expert views for well-recognised substances but also highlight gaps for certain emerging chemicals. This study highlights the importance of targeted, country-specific education campaigns and shows the added value of integrating public perceptions into HBM design and priority setting.

1. Introduction

The global chemical industry, valued at over $5 trillion in 2017, is projected to double by 2030, driven by rising demand in emerging economies and increasingly complex global supply chains [1]. Despite the potential societal benefits of chemicals, this still amplifies concerns about widespread human exposure to a diverse array of chemicals, originating not only from common sources such as air, water, and food but also from everyday products like food packaging, cosmetics, and household goods [2,3,4]. Recent studies have detected over 3600 food contact chemicals (FCCs), including per- and polyfluoroalkyl substances (PFASs), bisphenol A, and phthalates, in the human body, with approximately 100 classified as highly hazardous [5]. Persistent organic pollutants, heavy metals such as lead, mercury, cadmium, and endocrine-disrupting compounds are linked to chronic diseases, including cancer, diabetes, and neurodevelopmental disorders, and contribute to environmental damage through soil and water contamination [6,7,8,9,10,11]. These chemicals migrate from sources like food contact materials and cosmetics, as evidenced by extensive research [12,13,14].

Human biomonitoring (HBM) is a gold-standard method for assessing chemical exposures through biomarkers, informing population-level risk and regulatory strategies [15,16,17,18,19]. In Europe, the European Joint Programme Human Biomonitoring for Europe (HBM4EU) provided a coordinated framework for comparable HBM data and insights on public perceptions, aligning with the EU Chemicals Strategy for Sustainability and Zero Pollution Ambition [20,21], while the Partnership for the Assessment of Risks from Chemicals (PARC) further enhances chemical risk assessment capacity [22]. Globally, the World Health Organisation (WHO) has recognised HBM’s value and established the EHP (European Environment and Health Process) working group to promote its use in surveillance, exposure assessment, and harmonised chemical safety policies [23]. The policy impact of HBM is evident worldwide. In the United States, elevated blood lead levels identified through National Health and Nutrition Examination Survey (NHANES) contributed to the removal of lead from gasoline [24,25,26]. In Germany, data from German Environmental Surveys (GerES) and the Environmental Specimen Bank (ESB) guided recommendations to avoid mercury-containing amalgam fillings in children [27,28] and supported restrictions on phthalates in plastics [29,30]. Similarly, rising polybrominated diphenyl ethers (PBDEs) in Swedish breast milk samples prompted the phase-out of lower-brominated PBDEs [31]. These examples demonstrate that HBM not only advances understanding of chemical exposures but also drives public health and regulatory action.

Ireland has taken initial steps toward establishing a national HBM framework through the HBM4IRE feasibility study [32]. This study was conducted to identify the necessary criteria for implementing a national HBM programme, which included chemical prioritisation tailored to the Irish context. The study engaged with stakeholders including scientists, public health experts, regulators, and community representatives in identifying chemicals of concern and exploring programme design (via Stakeholder Forum and World Café) [32], which were all incorporated in the final chemical prioritisation [33].

A key innovation in the HBM4IRE study was the inclusion of public perception as a formal criterion in the chemical prioritisation process: an approach that goes beyond the traditional reliance on expert and regulatory input. While most countries prioritise chemicals based on policy relevance, exposure patterns, or expert consensus as seen in Belgium, Slovenia, France, the U.S., Latvia and initiatives like HBM4EU [34,35,36,37,38], Ireland uniquely integrated public insights to capture societal concerns and awareness gaps in its chemical prioritisation process [33]. This approach aims to identify any unique societal concerns or awareness gaps that might otherwise be overlooked in expert-driven processes.

Building on this rationale, public perception should be recognised not merely as supplementary input but as a critical determinant of both effective chemical management policies and the success of HBM programmes. Public awareness and perceptions influence trust, public support, and ultimately the success of regulatory outcomes. For example, a study of U.S. media coverage of chemical hazards (1990–2010) found that heightened concern particularly around vulnerable populations such as children drove state-level policy responses and ultimately built momentum for federal regulatory change [39]. Similarly, a large survey in Jiangsu Province, China (n = 1190), revealed that public risk acceptance of the chemical industry is shaped by perceived knowledge, accident impacts, perceived benefits, and trust in government, with demographic factors such as gender and income further influencing responses [40]. These insights are highly relevant for HBM programmes, which depend on public participation and trust; without them, data collection and subsequent policy action may face resistance or low engagement. Nevertheless, in Ireland, systematic evidence on public awareness and perceptions of chemical exposures is lacking. Despite growing media coverage of chemical exposures particularly concerning substances such as PFASs, endocrine-disrupting chemicals (EDCs), and heavy metals, there is a lack of research on how the general public in Ireland perceives the risks from chemicals. Public awareness remains limited, and no baseline data exists on the level of awareness and risk perceptions across different population segments. Filling this knowledge gap will assist in the development of targeted risk communication strategies and ensure that public concerns are reflected in policy needs. These considerations should be embedded in Ireland’s human biomonitoring programme, as effective decision-making requires an understanding of both scientific evidence and public perception.

To address this gap, the present study aims to demonstrate a structured methodological approach for capturing public awareness of chemical exposure sources and evaluating perceived harmfulness across priority chemical groups in Ireland. The study focuses on methodological development within the context of the HBM4IRE feasibility study, illustrating how public perceptions can be systematically integrated into chemical prioritisation process and HBM programme design. While the findings provide preliminary insights that may guide future large-scale research, inform targeted regulatory actions, and support public education initiatives, the primary objective of this publication is to demonstrate a methodological approach for incorporating social perspectives into chemical prioritisation process of human biomonitoring programmes.

2. Materials and Methods

The development of the social survey for the HBM4IRE feasibility study was guided by the structure and principles established under the HBM4EU initiative. The HBM4EU project had developed a social survey instrument aimed at capturing public awareness, and concerns related to chemical exposures, as well as attitudes toward HBM as a public health tool [41]. This established framework served as the foundational reference point for the Irish context.

To adapt and extend this survey for Ireland, the HBM4EU list of prioritised substances, which includes chemicals selected through a pan-European prioritisation process conducted between 2016 and 2018, was reviewed. The list comprised of well-characterised substances such as bisphenols, phthalates, cadmium, mercury, pesticides, and others based on exposure relevance, health risks, and regulatory importance [42]. The list was expanded to incorporate additional substances of high concern identified in national HBM programmes worldwide, including EU countries (Germany, France, Belgium, Norway, Slovenia, Czech Republic, and Sweden) and non-EU (US, Canada, South Korea, China, and New Zealand) [33]. These additions included quaternary ammonium compounds (QACs), disinfection by-products, tobacco alkaloids and volatile organic compounds (VOCs). A total of 24 chemical groups were finalised for the survey, ensuring they were analytically feasible for HBM and of emerging relevance in environmental health. It is important to note that the broad categories, such as “chemical mixtures” and “emerging substances”, although included in the HBM4EU priority list, were not represented in our survey, as these substances are umbrella categories rather than discrete, well-defined chemicals and translating them into individual, measurable chemicals for public perception assessment was challenging. In addition, in designing the questionnaire, “harmfulness” was presented as a general concept referring to perceived harm to people, without specifying the study population, exposure routes, and specific cohorts. This approach was intentional, as the objective was to capture broad public perceptions. The level of detail was intentionally reduced to ensure that the questions were easy to understand, concise, and not confusing for the general public, while also minimising participant fatigue and maintaining completion rates.

The finalised survey was created (see Supplementary Material S1) and distributed using SurveyMonkey, a widely used platform for survey design and analysis. It was disseminated from July to September 2023 via email lists, institutional websites, and social media channels of University College Dublin and the Environmental Protection Agency (EPA) Ireland. Sampling targeted residents of Ireland aged 18 and older. Participants were provided with information about the HBM4IRE project, survey objectives, and informed consent requirements, in accordance with ethical guidelines.

The awareness and perception were assessed sequentially for each of the 24 chemical groups using a two-question design. First, participants were asked whether they had ever heard of or knew about a given chemical group (Known/Unknown). Only those who indicated ‘Known’ were asked a follow-up question: “If known, could you select one of the options below on how you perceive this substance to be harmful to people?” Harmfulness was therefore measured as participants’ own perception of how harmful a substance is to people, using a 5-point Likert scale ranging from “Seriously harmful” to “Not harmful at all” shown in

Table 1. Likert scale categories used to assess perceived harmfulness of chemical groups among participants who indicate awareness of the substance. (adapted from our previous study [33], which informed the overall chemical prioritisation in the HBM4IRE feasibility study).

Perception of Harmfulness	Seriously Harmful	Moderately Harmful	Slightly Harmful	Not Harmful at All	Don’t Know
Scale	3	2	1	0	0

. Importantly, the perception question was skipped entirely if the participant indicated they were not aware of the chemical. This conditional design ensured that perception scores were collected only from respondents with awareness, avoiding speculative or uninformed responses.

As the perception questions were asked only if the respondent had already indicated awareness of the chemical, both “Not harmful at all” and “Don’t know” occurred within the group of participants aware of the chemical’s existence. “Not harmful at all” was interpreted as awareness without recognition of harmfulness, whereas “Don’t know” was interpreted as awareness of the chemical but not having the relevant knowledge of its harmfulness. Since neither situations provide a harmfulness level for different reasons, they were coded consistently as 0. This decision ensured comparability across chemical groups, avoided inflated harmfulness scores, and maintained a simple and interpretable scoring system appropriate for this study. Thereafter, corresponding to responses for each chemical, an aggregate perceived level of harmfulness was estimated as per Equation (1):

$$\left\{{NS}_j\right\}={\sum }_{i=1}^5{p}_i{\ast hs}_i$$

(1)

where ${NS}_j$ is the cumulative score for chemical j; “$p_i$” is the proportion of people who responded for a perceived level of harmfulness {${\mathrm{h}\mathrm{s}}_{\mathrm{i}}$}. and i ϵ [1, 5].

Participants were stratified into experts and non-experts based on their self-reported association with chemical management. This distinction was made to acknowledge their potential differences in familiarity with the chemicals/chemical groups, thereby enabling a more nuanced interpretation of the survey responses. All participants are considered part of the general public; however, we anticipated that individuals with experience or work in chemical management might have greater familiarity and understanding of chemical risks. To account for this, an expertise weight was applied: 0.7 (70%) for expert responses and 0.3 (30%) for non-expert responses. No additional efforts were made to recruit experts, the survey was open to all, and these individuals self-identified. This approach allows the framework to value informed perspectives while still reflecting the views of the broader public. We conducted a sensitivity analysis by varying the non-expert weight and recalculating chemical scores, confirming the robustness of our framework (see Supplementary Material S2: Sensitivity analysis varying non-expert weight for aggregate chemical scores). The aggregate survey score for chemicals was derived using Equation (2):

$$W_j=w_e\times H_{e,j}+w_{ne}\times H_{ne,j}$$

(2)

Noteworthy, separate scores were calculated for experts ($H_{e,j}$) and non-experts ($H_{ne,j}$) using the approach mentioned in general for {${NS}_j$}. ($H_{e,j}$) is the cumulative score for chemical ‘j’ estimated for expert group using Equation (1). Likewise, ($H_{ne,j}$) corresponds to cumulative score for non-experts using the same equation. (These results are presented in Figure 6 of the Section 3 (Results) which is the non-weighted individual scores) Thereafter, a weighted composite score or aggregate score ($W_j$) was estimated (Result shown in Figure 7). A detailed step-by-step demonstration of the aggregate score estimation method used in this study is provided for one chemical case (PFAS) in Supplementary Material S3.

The study received ethical approval from the University College Dublin Research Ethics Committee prior to survey implementation (Research Ethics Reference Number: LS-LR-24-251-Singh, and date of approval: 18 July 2024). Informed online consent was secured via the SurveyMonkey platform, ensuring participants understood the study’s purpose and their rights (the inbuilt information sheet and consent form within the SurveyMonkey platform are provided as Supplementary Material S4: Information and Consent Sheet). Participants were asked to confirm that they were 18 years or older and that they voluntarily agreed to participate in the survey. Only participants who selected “Yes” were able to proceed further with the survey questions All data in an anonymized form was securely stored in compliance with the General Data Protection Regulation (GDPR) and institutional data protection policies. Access to the data was restricted to authorised personnel only, and all measures were taken to ensure confidentiality and prevent unauthorised disclosure of participant information.

3. Results

3.1. Demographic Profile of the Survey Participants

The survey was attempted by 218 participants; however, a small proportion of the participants did not answer all the questions. The geographical distribution of responses to the HBM4IRE survey closely aligns with Ireland’s population demographics, with 42% of responses coming from Dublin County, the most populous region, home to over 38% of the population. Counties such as Galway (6.09%) and Wexford (6.60%) also demonstrated significant engagement, contributing to a regionally diverse dataset (Figure 1). The survey captured a diverse demographic cohort, encompassing a range of residential, educational, and professional backgrounds. In terms of residence, the majority of respondents were from urban areas (62.44%), with a significant portion representing rural areas (37.56%). This distribution ensures inclusivity and offers insights into both urban and rural perspectives on chemical-related concerns.

The length of residence in Ireland varied among the respondents, with a significant majority having lived in Ireland for extended periods. Over half (54.31%) reported living in Ireland all their lives, while 27.92% indicated having resided in the country for more than ten years (Figure 2). Smaller proportions had been in Ireland for shorter durations, with 7.11% each reporting residence for less than a year or between one and five years and 3.55% for six to ten years. This predominantly long-term resident population contributes generational perspectives and deep-rooted experiences to the survey findings.

The respondents exhibited a high level of educational attainment, with the majority having completed higher education. Specifically, 38.96% held a bachelor’s degree, 32.99% had a master’s degree, and 16.75% possessed a doctoral degree. A smaller proportion reported qualifications in vocational training (3.05%) or Post-Leaving Certificate (PLC) programmes (2.54%). This aligns with Ireland’s reputation as one of the most highly educated countries globally. Such an educational profile suggests that respondents are well-positioned to offer informed and nuanced perspectives on the perception of chemicals addressed in the survey, thereby strengthening the credibility and reliability of the collected data.

Regarding employment status, most respondents were government employees (55.33%), followed by those working in semi-state bodies (11.68%) and private employment (16.24%). Smaller groups included self-employed individuals (5.08%) and students (4.57%). Occupationally, a large proportion of participants were engaged in professional, scientific, and technical activities (43.15%), followed by human health and social work activities (19.80%). Other notable occupational sectors included administrative support services (6.09%) and information and communication (5.58%). This broad representation across sectors highlights diverse professional insights into chemical management.

Table 2. Demographic profile of HBM4IRE survey participants categorised by age, gender, urban or rural residence, involvement in chemical management, level of education, and employment status.

Characteristics	Category	n	%
Age	Under 18	0	0
	18–24	12	6.09
	25–34	24	12.18
	35–44	63	31.98
	45–54	62	31.47
	55–64	32	16.24
	65 and over	4	2.03
Gender	Male	86	43.65
	Female	109	55.33
	Other	0	0
	Prefer not to say	2	1.02
Residence	Urban	123	62.44
	Rural	74	37.56
Education	Leaving Certificate	5	2.54
	High school diploma/equivalent	1	0.51
	PLC courses	5	2.54
	Vocational training	6	3.05
	Apprenticeship	2	1.02
	Bachelor’s degree	76	38.58
	Master’s degree	65	32.99
	Doctoral degree	33	16.75
	Other	4	2.03
Employment status	Self-employed	10	5.08
	Private employee	32	16.24
	Government employee	109	55.33
	Semi-state bodies	23	11.68
	Apprenticeship	1	0.51
	Homemaker	3	1.52
	Retired	3	1.52
	Student	9	4.57
	Unemployed	3	1.52
	Other	4	2.03
Occupation	Agriculture/forestry/fishing	3	1.52
	Construction	8	4.06
	Wholesale/retail trade	1	0.51
	Transportation/storage	3	1.52
	Information/communication	11	5.58
	Professional, scientific and technical	85	43.15
	Administrative/support service	12	6.09
	Human health and social work	39	19.8
	Industry	1	0.51
	Financial/insurance/real estate	4	2.03
	Other	30	15.23
Association with chemical management	Yes	70	35.53
	No	127	64.47

presents the demographic profile of participants in the HBM4IRE survey, categorised by age, gender, urban or rural residence, involvement in chemical management, level of education, and employment status.

In terms of concern about chemical usage and exposure, responses varied. While 19.80% reported being extremely concerned, the majority (42.64%) expressed moderate concern, with 26.90% being somewhat concerned. Smaller proportions were slightly concerned (7.61%) or not concerned at all (3.05%). These results suggest that while awareness exists, perceptions of chemical risks differ across the population. Figure 3 depicts the level of concern among survey respondents regarding chemical usage and exposure, with the majority expressing moderate to extreme concern. Figure 4 illustrates the most important issues related to chemical exposure as identified by survey respondents, highlighting concerns about food contamination, water quality, air pollution, and consumer products.

3.2. Scoring of Chemicals by Two Respondent Groups in Ireland

A significant proportion of respondents (35.53%) reported being involved in chemical management as part of their work duties. Among these, most were affiliated with regulatory bodies (34.67%) or engaged in laboratory management (16.00%). Smaller groups participated in policymaking (14.67%), research and development (6.67%), and other related roles (Figure 5).

The chemical scores for chemicals were obtained from two distinct respondent groups: individuals working in or associated with chemical management (hereafter referred to as “experts”) and those not associated (“general public”).

Overall, experts consistently reported higher perceived harmfulness scores across most chemical groups compared to the general public (Figure 6). For instance, phthalates received a score of 1.46 from experts, compared to 0.84 from non-experts. Similarly, Bisphenols (1.62 vs. 1.07), Per- and Polyfluoroalkyl Substances (PFASs) (1.59 vs. 0.88), and Polycyclic Aromatic Hydrocarbons (2.06 vs. 1.44) showed notable gaps between the two groups.

Certain substances, such as lead (2.48 vs. 2.61), pesticides (2.35 vs. 2.36), mercury (2.44 vs. 2.28), and solvents (1.94 vs. 1.92), received high harmfulness scores from both groups, indicating a shared perception of risk.

On the contrary, substantial perception gaps were observed for chemicals like Di-isocyanates (1.54 vs. 0.60), Quaternary Ammonium Compounds (0.94 vs. 0.41), Aniline family compounds (1.19 vs. 0.24), and Perchlorate and other anions (1.02 vs. 0.36), suggesting a lower awareness of their potential harms among the general public. The weighted final scores reflect this disparity and offer a composite picture of risk perception across the sample population.

3.3. Final Aggregate Scoring of Chemicals Based on the Survey

The results from the survey on chemical groups reflect varying levels of concern and awareness among participants, highlighting how different chemicals are perceived in terms of their potential impacts on human health and the environment. The final score of the survey of several chemical groups stood out as particularly concerning to respondents, particularly the heavy metals. These included Lead (2.52), Arsenic (2.48), Mercury and Mercury Compounds (2.39), and Pesticides (2.35), all of which received the highest scores. Several chemicals, including Perchlorate and Other Anions (0.82), Quaternary Ammonium Compounds (0.78), and the Aniline family (0.90), scored the lowest, indicating that the majority of participants either have little concern or limited awareness of these substances. Though they are prioritised under the HBM4IRE list, these chemicals are less likely to be discussed in public health campaigns or regulatory initiatives in Ireland and across the EU, which may contribute to their lower concern among respondents (Figure 7).

4. Discussion

With the rapid growth of HBM across the EU and internationally, the development of national HBM programmes and the necessary preparatory steps are of vital importance. This priority has also been underlined by the establishment of the WHO EHP (European Environment and Health Process) Partnership on Human Biomonitoring, whose ambition is to provide sustainable, ongoing support for HBM studies and to enhance the capacity of countries to develop national programmes [23]. The present survey represents one such preparatory step. It was designed to capture public awareness and perception of chemicals of concern, thereby contributing to the prioritisation of substances and the identification of communication needs for future HBM programme in Ireland. Importantly, the survey builds on a previously developed HBM4EU survey but extends and improves it to provide more robust information on perceived perceptions of harmfulness. This approach not only informs the Irish HBM programme but also provides a transferable framework that can be adapted by other countries seeking to implement similar studies. Incorporating public perception into the prioritisation of chemicals for HBM is a novel approach within HBM programmes. Traditionally, chemical prioritisation and HBM programmes have relied heavily on expert-driven assessments of toxicity, exposure frequency, and regulatory relevance [43]. Our study extends the HBM4EU framework by adapting it into a national pilot context for Ireland and by systematically integrating public awareness and perceptions of chemical harmfulness. It is important to note that this work was conducted as part of a feasibility study, with the primary aim of testing whether public perception questions could be integrated into a HBM framework and chemical prioritisation process. Given Ireland’s aspiration to establish a national HBM programme and its ongoing first HBM cycle (under HBM4IE project funded by EPA Ireland and co-funded by PARC), where blood, urine, and serum samples will be collected from adults, these findings are particularly timely. They offer actionable insights for chemical prioritisation for HBM cycle and the development of effective communication strategies that connect technical exposure assessment with public understanding and perception. This study introduces a participatory approach that acknowledges the importance of aligning scientific priorities with societal concerns by integrating the perspectives of the general population, enhancing the effectiveness of national HBM programmes [37].

As the survey design was guided by the HBM4EU Social Survey template, it ensured methodological coherence with European best practices and enabled cross-national comparability of risk perception and awareness data. This alignment strengthens the relevance of the findings for policymakers and contributes to broader EU-level discussions on chemicals of emerging concern and public engagement in environmental health governance [21,44].

The results of the HBM4IRE social survey provide a comprehensive overview of the demographic profile and public perceptions of chemical exposure in Ireland, offering valuable insights into the factors influencing these perspectives. The findings provide critical insights into public perceptions of issues responsible for chemical exposure, revealing a notable pattern: issues subject to high levels of regulation, such as food contamination, water contamination, and air pollution are the primary concerns among the Irish public, while issues such as soil contamination, cosmetics usage and occupational exposures are perceived as less pressing. The high concern for food contamination, water contamination, and air pollution likely reflects public awareness about the robust regulatory frameworks around these areas in Ireland, such as the European Union’s food safety standards, water quality directives, and air quality regulations. These frameworks, enforced by agencies like the Food Safety Authority of Ireland (FSAI) and the Environmental Protection Agency (EPA), ensure frequent monitoring, public reporting and strong communication strategies, which may intensify public awareness of potential risks. For instance, the FSAI coordinates food safety enforcement, conducts inspections, and issues public alerts on recalls [45]. Similarly, the EPA monitors water and air quality for chemical pollutants and food waste, publishing data on platforms like Catchments.ie and Beaches.ie, with initiatives like the Food Waste Charter promoting risk awareness [46,47]. It also uses social media to share the key findings of reports and updates on chemical monitoring, such as PFAS contamination in water bodies [48].

The survey results indicated comparatively lower public concern regarding exposure from cosmetics usage, soil contamination, and occupational exposures. For the HBM4IRE programme, these findings highlight opportunities to align focus areas with the chemicals of greatest concern identified in the survey, which include pesticides, heavy metals, and VOCs in food, water, and air [33]. To address the concerns, the programme should prioritise HBM of chemicals associated with highly regulated pathways [33]. HBM can provide robust evidence to strengthen existing regulations and reassure the public about the effectiveness of current measures by quantifying exposure levels and identifying at-risk populations [49,50,51,52].

Simultaneously, the low concern for exposure due to cosmetics usage, occupational exposures, and soil contamination suggests a need for increased public education to raise awareness of under-regulated exposures. Initiatives such as community outreach, informational campaigns, and collaboration with local authorities could highlight the health implications of chemicals from personal care products (such as plasticisers/phthalates, preservatives/parabens, and UV filters) or soil contaminants like polycyclic aromatic hydrocarbons (PAHs) and legacy pollutants from former industrial sites. Evidence from multiple community-based educational interventions demonstrates that well-designed programmes can significantly improve awareness and encourage protective behaviours, particularly when culturally tailored and participatory methods are used. For example, an intervention in Puerto Rico increased polychlorinated biphenyl (PCB) awareness from 6.6% to 69.7% and reduced risky seafood consumption from 54.6% to 33% [53], while an arsenic education campaign in Bangladesh raised quiz scores from 8.5 to 14.1 (out of 20) and achieved a 53% well-switching rate [54]. Other studies, such as those involving Native American communities exposed to PAHs [55] and nail salon workers at risk from VOCs [56], also reported measurable gains in chemical knowledge and protective practices.

It is interesting to note that a significant difference was observed in the risk perception of chemical substances between experts (individuals working in or associated with chemical management) and the general public. Interestingly, a few chemicals such as lead, mercury, and pesticides scored high across both groups. This convergence likely reflects the influence of long-standing regulatory efforts, media coverage, and public health campaigns. For instance, lead has been subject to comprehensive regulation, particularly in the US, resulting in measurable health benefits [57,58,59]. At the same time, lead and pesticides received slightly higher harmfulness scores from non-experts (or nearly comparable to those of experts), suggesting that awareness of these chemicals is high even among the general public, likely due to historical exposure incidents, awareness campaigns and familiarity with regulatory frameworks, exposure limits, and ongoing monitoring practices in Ireland and the EU. Pesticides and mercury are also regulated, but the consistency and evaluation of these measures vary, with fewer assessments available on the effectiveness of mercury-specific policies [60,61,62]. In parallel, although the majority of survey participants, both those associated and not associated with chemicals, held university degrees, low scores were observed for certain emerging chemicals, such as UV filters, phthalates, and quaternary ammonium compounds. This suggests that higher educational attainment does not automatically confer familiarity with all chemical risks, particularly for individuals not professionally involved with chemical management or environmental health. This is supported by previous studies demonstrating significant knowledge gaps among educated populations even in laboratory settings. For example, one study in Italy found that only 46% of research laboratory workers, despite their advanced education, demonstrated good knowledge of chemical hazards [63], and another study in Trinidad reported that tertiary students in Trinidad exhibited high general safety awareness but had deficiencies in recognising specific chemical harmfulness [64]. These findings indicate that education alone does not ensure comprehensive knowledge of chemical risks, particularly for non-specialists or those not professionally involved in chemical management or environmental health, as in our study population.

The substantial underestimation of harm by the general public for lesser-known or emerging substances points again to critical gaps in public awareness. These chemicals, despite known health concerns such as respiratory issues and carcinogenicity, appear to be less recognised outside expert circles. For example, the general public underestimates the risks associated with PFAS exposure. Despite growing scientific and regulatory attention to PFASs due to their persistence, bioaccumulation, and links to serious health outcomes [65,66]. The relatively low concern expressed by non-experts may reflect limited public awareness or communication gaps regarding the widespread use of PFASs, such as in cookware, textiles, and firefighting foams and their long-term health implications. This is especially relevant given the limited literature on how local residents exposed to PFASs from industrial pollution perceive and respond to these risks [67].

The results highlight the need for targeted public education campaigns and transparent communication to bridge the understanding gap, especially given PFASs’ framing as “forever chemicals” due to their environmental persistence [68]. In addition, non-experts assigned lower concern scores to other chemicals such as phthalates and parabens, which are commonly found in cosmetics and linked to endocrine disruption [69,70,71]. Similarly, PAHs, which are associated with soil contamination from industrial sites, remain poorly recognised by the public despite their known carcinogenic properties [72].

The highest scored chemicals obtained after combining the scores of experts and non-experts are lead, arsenic, mercury and its compounds, pesticides, tobacco alkaloids, VOCs, solvents, cadmium, PAHs, and POP, reflecting strong alignment between expert and public concern regarding well-known toxicants. The presence of air pollutants such as VOCs and PAHs suggests growing awareness of environmental exposures beyond water and food, especially in urban and industrial settings. Overall, the results highlight how public perception is shaped by historical exposure incidents, policy interventions, and broader environmental health discourse.

Notably, many of these prioritised chemicals are also monitored in national HBM programmes worldwide and under initiatives like HBM4EU and PARC, which focus on substances with established health impacts, such as cadmium and arsenic, aligning research with public concern [44,73]. This alignment between public concern and ongoing scientific monitoring is encouraging, as it suggests that regulatory and research efforts are targeting substances of significant perceived and actual risk. It also reflects a positive trend toward evidence-based policy and investment in human biomonitoring of chemicals with well-documented health impacts, reinforcing the importance of continued surveillance and public engagement in chemical safety.

Study Limitations and Future Prospects

While the study provides valuable evidence to inform Ireland’s HBM programme, a few limitations must be acknowledged. In particular, the sample size of 218 respondents is relatively small compared with the national population, which may limit the extent to which the findings reflect broader public awareness and perceptions of chemicals of concern. The number of participants was constrained by the scope, timeline, and objectives of the HBM4IRE feasibility study, which focused primarily on testing methodological approaches rather than generating population-level prevalence estimates. Despite this limitation, the study provides valuable insights into the feasibility and added value of embedding public perception questions into HBM programme design. Another important limitation of this study lies in the design and length of the survey. Although the questionnaire was designed to minimise participant burden through concise phrasing, examples, and skip logic to remove irrelevant items, its comprehensive and scientifically robust design may still have been too lengthy or technical for members of the general public, particularly those with limited prior knowledge or interest in chemical-related issues. While we do not have formal evidence to quantify this concern, feedback from a few participants indicated that the survey could be overwhelming or difficult to complete. This may have influenced response rates or the depth of engagement with certain questions. It is important to highlight that participants who did not answer specific questions were excluded from analyses for those chemicals. Non-response was excluded cautiously, as it may reflect limited awareness or familiarity with the chemical rather than random missingness.

Not all people completed the survey. Missing responses were likely due to survey fatigue, as participants progressed through multiple chemicals and demographic questions. Another important consideration is the use of scientific terminology that may not align with everyday language. For instance, the survey used the term “bisphenol A,” whereas most people are more familiar with its abbreviation “BPA,” as commonly seen on plastic water bottles and food containers. Similarly, “PFAS” is often more effectively communicated using the term “forever chemicals,” which has gained traction in media and public discourse. Future surveys should aim to strike a balance between scientific accuracy and public accessibility, including the use of terms that reflect how chemicals are commonly discussed in daily life. Capturing such linguistic nuances can help improve comprehension and the quality of responses.

An indirect but important limitation of the current study is the selection of chemicals included in the prioritisation exercise. The list was restricted to substances that are currently measurable through established HBM techniques, given the study’s objective of informing the Irish HBM programme. However, this focus may exclude chemicals that are of concern to the public but are not yet covered by existing HBM methods. Future interventions of this work may benefit from incorporating an open-ended or exploratory component to identify emerging substances of public concern, which could then guide the development of new HBM methods and research capabilities.

Additionally, it is important to highlight that the term “harmful” in this study was intentionally left open to capture personal perceptions, which may have led to variability in interpretation across participants. The terms harm(ful), hazard, and risk can carry distinct meanings and connotations for the public compared with scientifically or policy-informed audiences. This inherent ambiguity is a key aspect of perception-based studies and challenging to be entirely resolved; nonetheless, future studies should be designed to specifically address this concern. Future work could explore more structured measures of perception, incorporate statistical testing, and investigate targeted risk communication strategies to bridge gaps between expert assessments and public understanding.

Largely, future HBM surveys could consider strategies such as questionnaire simplification, adaptive questioning (where respondents only see relevant questions), or breaking the survey into shorter sections to improve completion rates further. Additionally, future work should explore public perceptions across different sociodemographic groups (age, gender, education, occupation) and distinct working groups such as policymakers, industry professionals, regulators, and ministry officials, to gain a more nuanced understanding of chemical risk perception and support targeted communication strategies. While the study provides valuable insights into public perceptions of chemical risks in Ireland, careful attention to survey design, terminology, and chemical scope will be essential to improve future research and stakeholder engagement efforts.

5. Conclusions

This study contributes to advancing Ireland’s efforts in HBM initiatives by providing robust evidence on public perceptions of chemicals of concern in Ireland. The findings are expected to offer valuable insights for policymakers, public health professionals, and regulators, helping to shape inclusive and informed approaches to risk communication, regulatory prioritisation, and public engagement.

The findings carry several implications for designing effective communication strategies and policymaking in chemical safety. There is a clear need to develop more strategic awareness campaigns around emerging chemicals, such as PFASs in environment or newer endocrine-disrupting compounds. Using accessible terms such as referring to PFASs as “forever chemicals” can help make complex scientific concepts more relatable to the public.

At the same time, future HBM surveys should consider lessons from the present study’s limitations. The length and technical nature of the questionnaire may have discouraged some participation or limited engagement. Simplifying questionnaires, using adaptive questioning, or breaking surveys into shorter sections could improve completion rates and data quality. Additionally, striking a balance between scientific accuracy and public accessibility in terminology will be essential.