Systematic Review of Screening and Surveillance Programs to Protect Workers from Nanomaterials

Abstract

BackgroundScreening and surveillance approaches for workers exposed to nanomaterials could aid in early detection of health effects, provide data for epidemiological studies and inform action to decrease exposure. The aim of this review is to identify such screening and surveillance approaches, in order to extract available data regarding (i) the studies that have successfully been implemented in present day, (ii) identification of the most common and/or toxic nano-related health hazards for workers and (iii) possible exposure surveillance markers. This review contributes to the current understanding of the risk associated with nanomaterials by determining the knowledge gap and making recommendations based on current findings.MethodsA systematic review was conducted. PubMed and Embase were searched to identify articles reporting on any surveillance-related study that described both exposure to nanomaterials and the health indicators that were measured. Four reviewers worked in pairs to independently assess the eligibility of studies and risk of bias before extraction of data. Studies were categorised according to the type of study and the medical surveillance performed, which included the type of nanomaterial, any exposure details provided, as well as health indicators and biomarkers tested.ResultsInitially 92 studies were identified, from which 84 full texts were assessed for eligibility. Seven studies met all the inclusion criteria, i.e. those performed in Taiwan, Korea, Czech Republic and the US. Of these, six compared health indicators between exposed and unexposed workers and one study described a surveillance program. All studies were at a high risk of bias. Workers were exposed to a mix of nanomaterials in three studies, carbon-based nanomaterials in two studies, nano-silver in one study and nano-titanium oxide in the other study. Two studies did not find a difference in biomarkers between exposed and unexposed workers. In addition, differences in early effects on pulmonary function or neurobehavioral tests were not observed. One study found an increased prevalence of allergic dermatitis and “sneezing” in the exposed group.ConclusionsThis review of recently published data on surveillance studies proves that there is a gap in the current knowledge, where most of the surveillance-related studies reported do not follow a set format that provides the required information on ENM characterisation, the type of exposure and the measured indicators/biomarkers. Hence, there is very low quality evidence that screening and surveillance might detect adverse health effects associated with workplace exposure. This systematic review is relevant because it proves that, although surveillance programs have been initiated and preliminary results are being published, the current studies are actually not answering the important questions or solving the overall problem regarding what the potential health hazards are among workers either handling or potentially exposed to ENMs. The recommendations, thus proposed, are based on an ...

Current state of knowledge on the health effects of engineered nanomaterials in workers: a systematic review of human studies and epidemiological investigations

“…From previous investigations (10,11), it was expected there would only be a small number of epidemiological biomarker studies. Most of the extant epidemiological studies of nanomaterial workers met the inclusion criteria and were included in the review, although some methodological criticisms emerged from previous analyses of such investigations (10)(11)(12). The aim of this review was to consider the findings in terms of commonality or divergence (10) between studies, pointing out coherent links with supporting literature, involving both human and animal subjects.…”

“…Epidemiological studies of TiO 2 production workers show limited evidence of malignant or nonmalignant health effects, although the particle size was not specified (14,60,61). In 2010, the IARC reviewed epidemiologic data and found inadequate evidence to classify TiO 2 as a human carcinogen (12). However, lung tumors observed in rats following chronic inhalation of nano-sized TiO 2 included squamous cell keratinizing cysts, bronchoalveolar adenocarcinomas, and squamous cell carcinomas (62,63).…”

Methodological, political and legal issues in the assessment of the effects of nanotechnology on human health

“…419 Thus, cross-sectional studies using effect biomarkers are quite limited for drawing conclusions about the relationship between exposure to ENMs and observed effects, especially when the biomarkers used reflect early biochemical or functional changes lacking clinical significance. 4520 Furthermore, co-exposures frequent in the workplace and individual lifestyle factors require rigorous assessment to control for potential confounding biases. 15 Clearly, only a longitudinal follow-up of a large number of workers exposed to (the same) ENMs could ultimately resolve the question of health risks.…”

A human whole-blood model to study the activation of innate immunity system triggered by nanoparticles as a demonstrator for toxicity

“…Because of their widespread use, it has become important to evaluate their possible biological toxic effects. Concerns have been raised about associated health risks in the general population at the intended or unintended usage of NPs as well as to exposed workers during the manufacture of industrial NPs [2]. Another general conclusion that can be drawn is that further surface modifications are necessary in order to improve the biocompatibility of NPs intended for therapeutic use.…”