Surveys of Knowledge and Awareness of Plastic Pollution and Risk Reduction Behavior in the General Population: A Systematic Review

Abstract

Individual attitudes and knowledge can predict pro-environmental behaviors. Public surveys, therefore, can provide precious information, which can guide sensitization interventions. In this systematic review, we searched Medline and Embase, with no language or date restrictions, for surveys designed to measure in the general population the level of knowledge about different types of plastics, the risks associated with plastic pollution, and awareness of actions to reduce them. Survey tools were analyzed following the guide of Burns and Kho, and study methodological quality was assessed via the Appraisal Tool for Cross-Sectional Studies. We included 17 articles published from 2019 to 2024, mostly concerning European populations. The tools comprised a median of 13 items (range 7-50), and very differently formulated questions. Overall, 13/17 (76.5%) study questionnaires received less than 50% (<3.5) of the maximum possible score. The remaining four questionnaires obtained intermediate scores (between 3.5 and 5.3) indicating moderate quality. Most studies did not employ the appropriate cross-sectional survey methodology, only two studies statistically justified sample sizes, only three reported a sampling frame, and only two described a selection process that appears to be representative. In most cases, the instruments were not validated, and the statistical significance of key variables was not provided. The many shortcomings highlighted in this review emphasize the urgent need for methodological rigor when conducting survey studies, which are essential tools for public health.

Keywords: awareness; cross-sectional; environment; knowledge; plastics; pollution; public health; questionnaire; survey; systematic review.

Figure 1

Prisma flow diagram.

Figure 2

Methodological quality assessments of survey reports. Note: Each survey was evaluated by seven main questions and their subquestions. The sum of the points indicates the total quality of the survey (see the Quality Evaluation Tool subsection in the Section 2, and Table S6). Colors were assigned to each main question based on the following criteria: green circle if the sum of subquestions answered “yes” is ≥0.66; yellow circle if the sum of subquestions answered “yes” is 0.33–0.65; red circle if the sum of subquestions answered “yes” is <0.33.

Figure 3

Quality assessment of the 17 included studies using the Appraisal Tool for Cross-Sectional Studies (AXIS). Note: to facilitate consultation, colors were used as follows: green = Yes, red = No, blue = Cannot tell.

Figure 3

Quality assessment of the 17 included studies using the Appraisal Tool for Cross-Sectional Studies (AXIS). Note: to facilitate consultation, colors were used as follows: green = Yes, red = No, blue = Cannot tell.