Background: Mental well-being plays a pivotal role within the broader spectrum of health and illness, encompassing factors such as stress, depression, and anxiety. Nature-based therapeutic interventions have emerged as a promising approach to addressing these mental health challenges. This study seeks to assess the impact of these interventions on stress, depression, and anxiety levels. Methods: We conducted an extensive search for randomized clinical trials that examined stress, anxiety, and depression levels. The selected studies underwent a rigorous risk-of-bias assessment following the guidelines outlined in the Cochrane Handbook for Systematic Reviews. Results: Our review encompassed findings from eight publications. Among them, two studies measuring cortisol levels revealed significant differences between the pre-test and post-test measurements within the intervention groups. In two studies that employed the Stress Response Inventory, a significant decrease in stress levels was observed within the intervention groups in contrast to the control groups. However, no significant differences were noted in studies that utilized the Restorative Outcome Scale. In the assessment of anxiety and depression levels, three studies employed the Positive and Negative Affect Schedule, while four studies utilized The Profile of Mood States scale; none of these studies demonstrated significant differences. Conclusions: The current body of evidence offers limited support for advocating nature-based therapeutic interventions as a primary approach to reducing stress, depression, and anxiety.

During and after the pandemic caused by the SARS-CoV-2 virus, the use of personal care products and disinfectants increased in universities worldwide. Among these, quaternary ammonium-based products stand out; these compounds and their intermediates caused substantial changes in the chemical composition of the wastewater produced by these institutions. For this reason, improvements and environmentally sustainable biological alternatives were introduced in the existing treatment systems so that these institutions could continue their research and teaching activities. For this reason, the objective of this study was to develop an improved culture medium to cultivate ammonium oxidising bacteria (AOB) to increase the biomass and use them in the treatment of wastewater produced in a faculty of sciences in Bogotá, D.C., Colombia. A Plackett Burman Experimental Design (PBED) and growth curves served for oligotrophic culture medium, and production conditions improved for the AOB. Finally, these bacteria were used with total heterotrophic bacteria (THB) for wastewater treatment in a pilot plant. Modification of base ammonium broth and culture conditions (6607 mg L⁻¹ of (NH₄)₂SO₄, 84 mg L⁻¹ CaCO₃, 40 mg L⁻¹ MgSO₄·7H₂O, 40 mg L⁻¹ CaCl₂·2H₂O and 200 mg L⁻¹ KH₂PO₄, 10% (w/v) inoculum, no copper addition, pH 7.0 ± 0.2, 200 r.p.m., 30 days) favoured the growth of Nitrosomonas europea, Nitrosococcus oceani, and Nitrosospira multiformis with values of 8.23 ± 1.9, 7.56 ± 0.7 and 4.2 ± 0.4 Log₁₀ CFU mL⁻¹, respectively. NO₂⁻ production was 0.396 ± 0.0264, 0.247 ± 0.013 and 0.185 ± 0.003 mg L⁻¹ for Nitrosomonas europea, Nitrosococcus oceani and Nitrosospira multiformis. After the 5-day wastewater treatment (WW) by co-inoculating the three studied bacteria in the wastewater (with their self-microorganisms), the concentrations of AOB and THB were 5.92 and 9.3 Log₁₀ CFU mL⁻¹, respectively. These values were related to the oxidative decrease of Chemical Oxygen Demand (COD), (39.5 mg L⁻¹), Ammonium ion (NH₄⁺), (6.5 mg L⁻¹) Nitrite (NO₂⁻), (2.0 mg L⁻¹) and Nitrate (NO₃⁻), (1.5 mg L⁻¹), respectively in the five days of treatment. It was concluded, with the improvement of a culture medium and production conditions for three AOB through biotechnological strategies at the laboratory scale, being a promising alternative to bio-augment of the biomass of the studied bacteria under controlled conditions that allow the aerobic removal of COD and nitrogen cycle intermediates present in the studied wastewater.

Introduction: This pilot study was conducted as part of the project "Effects of Nature Immersion Therapy 'Vitamin N' on Stress Levels in Healthcare Workers in Bogotá: An Intervention Evaluation Study, 2022-2024." Objective: To evaluate the benefits of nature immersion in an active working population, with the aim of reduce perceived stress and anxiety, improve sleep quality, and regulate cortisol levels in saliva. Methodology: A longitudinal study was conducted using a non-probabilistic consecutive sampling method. The intervention took place once a week for one hour per session over the course of a month. Measurements were taken before and after the nature immersion, and participants were divided into three groups (control, parks, and forests). Psychological scales were used to assess perceived stress (PSS-14), subjective fatigue (Yoshitake), anxiety (STAI), and sleep quality (Pittsburgh). Additionally, saliva cortisol levels were measured in a subsample. Differences in mean scores between groups were estimated. Results: The intervention groups in forests and parks showed an average reduction of 2.6 points on the PSS-14 scale, while the control group showed a reduction of only 0.4 points. A decrease in general fatigue was observed in the parks group, but there were no significant changes in physical or mental fatigue. STAI levels did not change in any of the groups after the intervention. Although the intervention groups showed a slight improvement in sleep quality, it remained moderate and not statistically significant. Finally, a reduction in cortisol levels was observed in the intervention groups after the therapy. Conclusions: The results suggest that nature immersion therapy may have beneficial effects in reducing stress and fatigue, as well as in improving sleep quality and regulating cortisol levels in actively working individuals.

Background: Healthcare professionals experience high levels of stress due to demanding work, especially in metropolitan areas. Nature-based interventions offer potential mental health benefits. This randomized intervention study aimed to evaluate the effects of nature immersion therapies on mental health outcomes in healthcare workers with different psychological risk in Bogota, Colombia. Methods: During a period of 6 months, a total of 82 healthcare workers from two institutions were assigned to three groups: two exposed weekly to nature (parks and forests) and one control group with monthly conventional interventions. Psychological assessments of stress, anxiety, fatigue, and sleep quality were conducted at three time points (baseline, three, and six months of intervention). Cortisol Awakening Response (CAR) was measured monthly using immunoassay. Results: A decrease in the proportion of participants reporting high levels of perceived stress was observed in both intervention groups. Both forest and parks interventions significantly reduced anxiety and fatigue, while sleep quality improved only in the forest group. Multivariate analysis found a negative association between fatigue and forest intervention, as well as significant differences in CAR concentrations across groups over time. Conclusions: This study provides evidence that nature immersion therapy, particularly urban forests, positively impact mental and physical health, reducing stress, anxiety, fatigue, and CAR levels, and could be considered as an effective intervention to enhance workers’ resilience to stress, benefiting their overall health and well-being.

Background: The mental state is important in the health/illness process. Including stress, depression and anxiety. Nature immersion therapies have been implemented as a valid method for reducing these disorders. The aim will evaluate the effect of forest intervention therapies on levels of stress, depression, and anxiety. Methods: We searched for randomized clinical trials related to stress, anxiety and depression levels. Risk of bias was assessed according to the guidelines of the Cochrane Handbook for International Systematic Reviews. Results: We identified and synthesized eight publications. Two studies for cortisol showed significant differences between the pre-test and post-test levels in the intervention groups. One study including Natural killer cells, that reported a significant decrease in the intervention group compared to the control group. Two studies used the Stress Response Inventory, indicated a significant reduction in stress levels in the intervention group compared to the control group. Regarding Restorative Out-come Scale, no significant differences were found. Three studies were selected for the evaluation of anxiety and depression levels according to the Positive and Negative Affect Schedule. Four studies used The Profile of Mood States scale; no significant difference was observed. Conclusions: There is limited evidence to recommend forest bathing for reducing these disorders.