The interactions between one’s local microclimate and the physiological and neurological responses of the body and mind can be explored in a relatively low-cost way from the perspective of citizen science.

Citizen science is research conducted by those who are not necessarily full-time professionals and experts in their respective domains. It has become an important part of the research process and can be done from anywhere globally, especially in disciplinary fields in which observational skills can be more important than expensive research-grade or industrial-grade equipment. 

In recent decades, the number of citizen science projects has expanded. Today, many citizen scientists work with professional counterparts on projects that have been specifically designed or adapted to give amateurs a role, either for the educational benefit of the volunteers themselves or for the benefit of the project (^[1]). For example, much of our current understanding about our natural environment, including the effects of climate change, is derived from data that have been collected, transcribed, or processed by members of the public (^[2]).

The rise of citizen science can be attributed to readily available technical tools for disseminating information about projects and gathering data from the public. The internet and the spread of mobile computing, such as smartphones, are the most significant developments. Citizen science also has been enhanced by open-source software, statistical tools, and computational techniques that remove many of the barriers to compiling and analysing complex data sets. Computers and accessible interfaces have made participation possible for groups that previously were not reached or well served by citizen science (^[2]). 

^[3] have found strong evidence of scientific outcomes from data collection and data processing citizen science projects. They have also suggested evidence that citizen science projects achieve participant gains in knowledge about science knowledge and process, increase public awareness of the diversity of scientific research, and provide deeper meaning to participants. They have further argued that citizen science could contribute positively to social well-being by influencing the questions being addressed and giving people a voice in local environmental decision-making. This latter point harkens back to the importance of learner agency which has been briefly discussed in the preceding section. Students using their natural inquisitiveness to investigate a topic they are passionate about develop scientific skills in a self-directed manner. 

A microclimate is a small area within the surrounding larger area with a different climate (^[4]). Any given climatic region therefore comprises many other types of microclimates, which vary in characteristics from the region as a whole. Because our planet in general is broadly conducive to life, we – as humans – have populated its land masses. Comparing the human scale to that of the various habitats in which we live, the difference of these scales means that changes in the climates of these habitats may disproportionately affect the conduct of our daily activities.

At local scales, activities associated with land use and land cover changes and urbanization induce impacts such as changes in atmospheric composition in water and energy balances and changes in the ecosystem (^[5]). By definition, ecosystems are interconnected, therefore a small change in any component can result in non-linear effects elsewhere. For example, according to a study conducted by ^[6] on the influence of different air temperature step-changes on human health and thermal comfort, perspiration, eye-strain, dizziness, accelerated respiration and heart rate were all sensitive self-reported symptoms.

Due to global climate change and intensifying urban heat island effects, urban living environments have deteriorated, becoming increasingly detrimental to human thermal comfort and health, not only psychologically, such as in terms of thermal sensation, mood, and concentration, but also physiologically by way of, for example, sunburn, heat stroke, and heat cramps (^[7]).

Electroencephalography (EEG) is used as a means of identifying human stress level as it has already been proved that there is a significant correlation between levels of psychological stress and EEG power (^[8]). In other cases, EEG data are also strongly related to the changes in human physiological health, such as in heart rate variability (^[9]).

With regard to the technicalities of the different brainwaves, the gamma, beta, alpha, theta, and delta waves correspond to the frequencies of 0–4 Hz, 4–7 Hz, 8–12 Hz, 12–30 Hz, and 30–100+ Hz, respectively.

Brain activities around the frontal, temporal, and occipital lobes are commonly collected, analyzed, and used to detect fatigue and attentiveness (^[10]). EEG signals can be analyzed in the time domain, as in the case of event-related potentials (ERP) (^[11]), as well as in the frequency domain, as with the spectral content of frequency bands (^[12]). More recent EEG analysis methods involve the use of functional connectivity (^[13]) and source separation (^[14]) algorithms. Signal source separation methods for EEG signal analysis, such as the Moore–Penrose pseudoinversion, as proposed by ^[14], allow the spatial identification of the different sources in the brain responsible for specific neural activations. Recently, inter-subject correlation (ISC) of the EEG has been proposed as a marker of attentional engagement (^[15], ^[16], ^[17]). With the aforementioned implications of different brainwaves, EEG data can be sensibly used as a means of investigating human productivity (^[18]).

Until recently, measuring encephalographic (EEG) data required the use of industry-grade headsets which are expensive and associated with expensive laboratory infrastructure.

New developments in encephalography have permitted EEG instruments to be deconstructed such that the electrodes (alone) are now available for purchase by the general public, greatly reducing the cost of exploration.

Further, such standalone electrode kits are dry electrodes, further democratizing EEG experimentation because extensive preparation of the scalp and hair are no longer required.

The trade off for these standalone kits is between cost and accuracy.

Recent work reported by ^[19] and ^[20] describe a small-scale study referred to as ‘Learning at the intersection of AI, physiology, EEG, our environment and well-being (the Life2Well Project)’, in which data from EEG headsets was complemented by those obtained from smartwatches (namely heart rate and its variability and body temperature and stress score). Identical units of a wearable device containing environmental sensors (such as ambient temperature, air pressure, infrared radiation, and relative humidity) were designed and worn, respectively, by five adolescents for the same period. More than 100,000 data points of different types — neurological, physiological, and environmental — were eventually collected and were processed through a random forest regression model and deep learning models. The study established that the most influential microclimatic factors on the biometric indicators were noise and the concentrations of carbon dioxide and dust. Subsequently, more complex inferences were made from Shapley value interpretation of the regression models. Such findings suggest implications for the design of living conditions with respect to the interaction of microclimate and human health and comfort.

These results bear out causal linkages reported by similar studies in the field. For example, ^[21] have documented positive relationships between ambient temperature and both body core temperature and corneal temperature, and ^[22] have documented positive relationships between relative humidity and body core temperature.

^[23] have documented that high cognitive functions are associated with higher heart rate variability, and ^[24] have documented that heart rate variability is inversely correlated to heart rate; this reinforces our conclusion that the frontal and occipital lobes are most related to heart rate, which generally suggests that high cognitive functions lead to lower heart rate.

As for heart rate, ^[25] found that “carbon dioxide excess causes an increase in ventilation volume by virtue of a greater depth of breathing, the frequency decreasing slightly. The heart rate goes up with increasing carbon dioxide concentrations”. ^[26] have shared that “the influence of atmospheric pressure and temperature on the incidence of acute aortic dissections may be explained by an increase in sympathetic activity, which is responsible for higher blood pressure, and heart rate”. Another factor that affects heart rate is dust concentration. As suggested by ^[27], elevated particulate levels were associated with increased mean heart rate and decreased overall heart rate variability. Sound also plays a part in affecting heartbeat, according to past research — for example, that of ^[28] — the higher the noise level, the higher the heart rate. Heart rate drops at night when humans are sleeping. According to ^[29], “a balance of impulse from the sympathetic and the parasympathetic nerves determine a person’s baseline heart rate. Interestingly, in experiments where a person’s nerve supply is blocked, the heart rate is often higher; this would suggest that the parasympathetic nerve impulses that serve to slow the heart rate down are the predominant force under normal resting conditions. This is particularly evident at night when most people have a significant drop in heart rate”.

In terms of the associative relationships between microclimate and mental health, ^[30] have observed that “we find that higher temperatures increase emergency department visits for mental illness, suicides, and self-reported days of poor mental health”. This position is congruent with that of the present study, in which extremes of sound levels were associated with both lower mental well-being, as indicated by the stress score ^[31].

Within the context of anthropogenic climate change, the extent to which carbon dioxide concentrations affect health and well-being is of interest ^[32]. ^[33] have reported that well-being — as well as capacity to focus attention — both decline when carbon dioxide concentration in the air increases nearly tenfold to 3000 ppm.

This entry is adapted from the peer-reviewed paper 10.3390/su141710769