Knowledge and perception about climate change and human health: findings from a baseline survey among vulnerable communities in Bangladesh

The adverse effect of climate change on human health has been recognized relatively late in the development of climate science and policy making [1, 2]. The recent Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) reinforces the need for societies to take adaptive actions to protect human health from the adverse consequences of climate change [3]. Climate sensitive health determinants and outcomes pose a threat to public health in Least Developed Countries (LDC) [4–6]. To protect health, highly strategic interventions for adaptation will be needed over the next 20–30 years in LDCs such as Bangladesh [7–9].

Climate change (CC) related health risk is a multidimensional and cross cutting issue. To date, a number of studies have suggested that peoples’ perception of and attitude towards CC risk is closely related to adaptative behaviour and mitigation action [10–12]. However, few such studies have been carried out in developing countries [13–16]. Bangladesh is on top of the IPCC risk index of climate victims since 2007 [17].

In this context, epidemiological research has a major role to play in combating CC-related adverse health effects. In a recent cross-sectional study from two villages, one from the northern and another from the southern part of Bangladesh, households’ (n = 450) perception of human health risks were explored, which suggested the need for further research with a larger sample size to allow generalization [18]. Another study revealed that the public perceptions towards CC, and its impact on health, may inform policies to cope with associated health challenges of CC [19]. In some studies, lay people perceived CC with misconceptions and misunderstandings about its cause and effects [20–22]. These misunderstandings have the propensity to cause fear about the consequences of CC [23]. However, environmental change management and associated education from the government are important to build resilience among the vulnerable communities [24].

Knowledge of CC is a necessary precursor for people to adapt appropriately. The health sector of Bangladesh does not have evidence-based strategies for health adaptation to CC. A survey undertaken by the Ministry of Health and Family Welfare of Bangladesh forms the basis of a future cohort study. Such a study is needed to expand our knowledge of evidence-based translational research, particularly in the context of being one of the most vulnerable LDCs. The objective of this study was to collect baseline data on knowledge and perception of CC, and the awareness of prevalence of climate sensitive diseases, in selected vulnerable areas of Bangladesh. We also collected baseline data on CC-related diseases such as malaria, Dengue fever, pneumonia & diarrhoeal diseases. This paper focuses on knowledge and perception.

The results of this study provide useful information for policy makers and other stakeholders in the health sector of Bangladesh, so they can better respond to the challenges of CC and their effects on health.

This study, to the best of our knowledge, is the first large-scale quantitative attempt to assess the knowledge and perceptions of the vulnerable communities in Bangladesh about CC and its impact on health. The findings provide important insights into what people think and believe from their experience at the grassroots level. The household participants were from the rural areas that are vulnerable to climate change [25]. Since we interviewed the heads of the households, most of the participants were male. The majority of participants were relatively poor and had little formal education with an agro-based livelihood, which is consistent with the national level data [26]. However, they have a clear perception about the change in climate and associated variability in temperature, rainfall, salinity and sea level, and the effect of these changes on their health. Knowledge and perception studies on CC and its associated health impact had been conducted in the Philippines [27], Vietnam [28], United States of America, Canada, and Malta [29], Nigeria [30], Nepal [31], Bangladesh [24], India [32], Australia [33], and China [34]. A previous cross-sectional study of two villages in Bangladesh had the limitation of generalizability of their findings regarding households’ perception of CC and human health risks [24]. In our study, we used a similar approach but our sample size was larger, more representative and better distributed geographically among vulnerable communities.

Out of 6720 participants, slightly more than fifty four percent had knowledge of ‘climate change’. Almost 46 % of the vulnerable community had not heard about CC, which might be a concern for the policy makers in health sector to provide adequate community level training on CC and its impact on health through the community clinics. The results are similar in two other studies conducted in LDCs, Nigeria [30] and Nepal [35], where 54 % and 51.3 %, respectively, of the participants reported they know about ‘climate change’. From our study, of those who had knowledge about CC, the majority named mass media (television, radio, newspaper etc.) and neighbours as their source. Very few people mentioned hearing about CC from teachers, Imams, health workers and non-governmental organization (NGO) workers. This indicates that mass media and discussions in the neighbourhood are important source of information. Opinion leaders such as teachers and imams of mosques, and service providers such as health workers and NGO workers need formal training on CC and its impact on health in the field level. There is a sectoral gap of engagement from the government system with health and environmental issues. This is consistent with the study conducted in Nepal [35]. Overall, our study highlights that mass media coverage, especially through community radio and television, is currently the major source of information about CC.

Most of the participants believed that there had been a change in climate in the 10 years preceding the interview. This perception is supported by data collected at national level on the climate in Bangladesh. Data from the Bangladesh Meteorological Department (BMD) for the periods of 1951–2011 show that for any ten-year period the temperature was higher and rainfall less predictable than in the preceding ten years [36]. Other countries such as Jamaica, Vietnam, and Nepal reported identical findings for their studies among a similar population [23, 28, 35]. With regard to causes or reasons for CC, most of our participants mentioned deforestation followed by population growth and industrial effluents. The other less scientific reasons given by the participants, such as black smoke of vehicles, could be due to their low level of education and less exposure to the scientific facts by virtue of their occupation. These results also supported by other studies carried out in Bangladesh and other LDCs such as Nigeria and small island countries such as Trinidad and Tobago [30, 37].

The perceptions of vulnerable people are also consistent with the national level findings. Annual maximum temperature over Bangladesh is increasing by 0.09 °C but annual minimum temperature is increasing by 0.10 °C. The rate of increase of the annual minimum temperature is higher than that of the annual maximum temperature [38]. The annual average rainfall over Bangladesh is increasing by about 10.6 mm per decade whereas monsoonal rainfall over Bangladesh is decreasing by 7.6 mm per decade [39]. The participants also had the perceptions that episodes of extreme weather events such as cyclones, floods, storm surges, heavy rains within a short time, and droughts had increased compared to ten years earlier. It has been observed from the BMD database that the frequency of cyclones has been increasing in every decade since the 1970s [40]. Bangladesh evidenced ten severe floods during the last 40 years. Every 4–5 years severe floods inundate about 60 % of the country. In 2007, two successive and damaging floods occurred in the same season [41]. It has been found that the frequency of heavy rainfall in June, July and August has increased over the last few decades [39].

With regard to the sea level rise, the perception of the coastal participants from Borguna, Bagerhat, Cox’s bazar, Khulna and Satkhira is supported by historic data on sea water level rise in three of the coastal districts: Bagerhat, Satkhira and Khulna. These data show that the mean annual water level has risen by 4.5 mm/year in about 20 % of the total area of these three districts, which is attributed to the global sea level rise associated with anthropological activities [42]. The perception of our participants regarding salinity intrusion and increase in water salinity is also supported by another evidence-based study [43].

Participants strongly agreed that agricultural food crop production had declined during the last 10 years, and population health had been adversely affected by CC in their villages. This has serious implications regarding food security and livelihood. The number of deaths from drowning and snake bites supports other community-based studies in Bangladesh [44, 45], although the incidence was higher in our study because of the increase in the number of extreme weather events. This finding has important implications for local level planning and policy development. Moreover, understanding the concerns of people about increased health care expenditure after the extreme weather events may help policy makers to develop and implement apprpriate adaptive measures for health adaptation.

In our study, heads of households with higher levels of education were more likely to be aware of CC than those with lower education levels. Other studies also reported that CC awareness most strongly depended on the respondent’s level of education [27, 31, 46]. In the course of educational development of Bangladesh the availability of schools in rural and remote areas was a major factor in students’ drop out and people’s education level. Our study suggests that schools play an important role for increasing knowledge on CC and associated adaptation issues.

Our study has several strengths. We surveyed a large number of households. Furthermore, the study recruited participants from an array of geographic locations known for their susceptibility to CC. This makes the findings from this study relevant to other CC-vulnerable areas of Bangladesh. A further strength is the collection of data with local context in association with how extreme weather events were experienced. The findings will be useful for developing strategies to induce individual and community behaviour change to better cope with CC and make adaptations to minimise health issues. The findings could be used as baseline for a future cohort study. There were a few limitations to the study, including the recall bias, as we relied on the previous experiences and subjective judgements of the head of the households. As 92.9 % of participants were male, female perception was not considered. Peoples’ perception on CC and its impact on health could not be checked against real-time data. Such data could be collected in future to allow estimating the accuracy of community perceptions.

The knowledge level of the study participants on CC was more than our assumption (54 %) and the perception of vulnerable communities on changing climatic factors and their impacts on health was higher (94 %). The public health sector needs to be engaged more in primary health care by training health workers at field level to address CC and health issues. Level of education is an influential factor to understand CC and its impact on health. Based on these key findings, policy makers can develop effective communication strategies for the vulnerable communities in Bangladesh and similar LDCs to protect human health from the adverse effect of CC. To protect future generations child-centred educational intervention at school level on CC and health adaptation could be explored by further research [47].