The management of this crop by flooding requires more water per unit area than in other irrigation systems.In Brazil, the Federal States that produce rice in greater quantities are Rio Grande do Sul, Santa Catarina, and Tocantins, responsible for, respectively, 73%, 8%, and 11% of national production.In general, the rice crop is produced from irrigation by furrows or flooding.Although the levels of exposure of receptors to hazard may differ among the irrigation methods, the similar approach was adopted in the application of the methodology, as both take into account the flooding of the area.It is also worth noting that the SqMRA methodology must be applied in each project, individually, considering that the exposure levels may vary depending on the local characteristics and operational conditions of irrigation, harvesting, and storage.Thus, this generalized approach, adopted in the present study, is configured only for scientific studies, since the action can lead to a high degree of uncertainty.The data adopted for the application of the SqMRA methodology in rice cultivation in Brazil are presented in Table 8, according to the model previously described its stages and steps.Notes: 1 The SqMRA was applied in two scenarios, in which the first considers the effluent to be disinfected , and the second considers the reality of sewage treatment conditions in Brazil.2 Inhalation is attributed to aerosols,hydroponic gutter generally produced in a sprinkler irrigation system.Although intense winds can also produce these types of micro-droplets in flooded systems, inhalation was not scenarioized in the present paper, for simplification purposes.

However, in cases of application of the methodology in places with the possibility of high winds, it should be adopted for farmers and neighborhoods.The barriers adopted, defined as actions after the harvest, relate only to consumers since the farmer harvests the rice in nature.Given the perspectives and the Brazilian reality, in terms of the quality of treated wastewater, the SqRMA was applied in two different scenarios.In the first one, we chose to adopt Hazard equal to 7, due to the prerogative that a disinfected effluent guarantees more safety to the practice.However, the reality about wastewater treatment in Brazil shows that most of the effluent is treated at a secondary level, without disinfection.Thus, the second scenario relies on the application of the methodology, considering Hazard equal to 9.The complete spreadsheet is available as Supplementary Material.This spreadsheet was developed to facilitate the use of the methodology in other applications and regions, but care must be taken, each case is a case and this methodology represents a real portrait of this case.However, it is important to pay attention to the indiscriminate use of the available spreadsheet, since the user must always apply it with great care, considering the real local characteristics of each irrigation water reuse project.The results presented in Table 6 demonstrate the feasibility of applying water reuse for rice cultivation in Brazil, about aspects of epidemiological risk.As expected, and in accordance with previous observations from other authors, there is an estimate of a higher risk of microbiological contamination for the farmer than for other receptors.Despite the high possibility of contact between the farmer and the RW, the estimated global risk is still in the acceptable level.

In the case of the neighborhood, the risk is greatly reduced because the irrigation method is different from sprinkling and presents a lower possibility of producing micro-droplets that could be inhaled, as already mentioned.But still, it is in the acceptable category.For the consumer, low risk was also expected, due to the processing and cooking of the rice before consumption.However, it should be noted that these risk values may vary depending on the specifics of the configuration of each reuse system, since there may be situations that enhance certain types of contact.For this reason, to calculate the global risk, two procedures were adopted: i) considering the three receptors adopted in the study; and ii) considering only the 2 main receptors involved since the possibility of several receptors, with multiple handling criteria, involved after harvest could change the final value of the global risk.Thus, should be emphasized that for the application of the methodology in a real project, all possible receptors, from irrigation to the final consumer, must be taken into account in conjunction with the food safety procedures needs according to respective regulations, when in place.It should also be noted that when considering all workers involved in the production process of rice irrigated with RW, is possible to minimize risks by introducing capacity building and systematic use of equipment and safety habits.The States of Rio Grande do Sul and Santa Catarina, identified in the present study as responsible for 80% of the Brazilian production of rice, are comprised, almost entirely, in the River Basin of Uruguai andAtl^antico Sul and require, in general, approximately 382 m3 /s of water for irrigation.However, the two RBs present a service rate with domestic wastewater treatment at 30%.

Similarly, the RB Tocantins-Araguaia, which involves practically the entire State of Tocantins, has a demand of approximately 60 m3 /s for irrigation but also has a low rate of wastewater treatment.The relationship between the Brazilian states highlighted in the study and the River Basin Districts also highlighted can be seen in the schematic map in Fig.3.The scenario of high demand for water for irrigation and low production of treated effluent shows the difficulty of structuring water reuse, although the water demand for rice crop production in these regions is high and the risk of contamination of human beings is moderate, as demonstrated by the application of methodology.The RW was defined in two categories to assess the potential for reuse in Brazilian RB, as a function of water quality: Category 1 – RW from wastewater treatment plants that have an organic matter removal higher than 80%; and Category 2 – RW from wastewater treatment plants which, in addition to having an organic matter removal of more than 80%, have disinfection.In this sense, considering the three RB , the potential for supply of reclaimed water in Category 1 is 2.53 m3 /s and in Categories 2 , of 1.12 m3 /s.Since Category 2 , equivalent to Hazard equal to 7 , represents the lowest available water potential for reuse, it was decided to repeat the process of applying the SqRMA methodology, considering hazard equal to 9, which represents Category 1.The results for this reiteration can be seen in Table 10.This reiteration in the application of the methodology presents a very relevant result, in which when offering water corresponding to a secondary effluent , even the estimation of risk for the farmer changing from acceptable to unacceptable, the overall risk remains in the acceptable level, although quite close to the limit of the maximum value.Furthermore, the risk for the farmer can be reduced with equivalent barriers, such as rubber gloves and boots, consequently reducing overall risk.In this sense, it can be highlighted that Uruguai, Atlantico Sul, and Tocantins-Araguaia River Basin have a high potential for the application of water reuse in the irrigation of rice crops by furrows or by flooding, with an acceptable risk of microbiological contamination of human beings involved in the practice.

However, it should be noted that the study deals with a generalized scientific approach and, in the case of a real application, all those involved must be carefully evaluated and the scenarios must be exhaustively studied, also considering the use of additional risk minimization means, such as equipment and safety habits among the workers in each sector, to provide more safety for the practice.It is also noteworthy that in Asia, the largest producer of irrigated rice in the world, the crop represents 40–46% of the irrigated area among all other crops.The water reuse in China has become the main objective of WWTP in the new era of wastewater treatment in the country.In this sense, a good way to solve the problem of water scarcity is to increase water productivity, corroborates the results of the present research.In the case of irrigated rice, it is important to determine the economic and energy implications when considering water reuse options to improve water productivity at the system level.The novel coronavirus has killed millions and shut down entire countries.Yet the danger was not always this clear.In late December 2019, China reported over 40 cases of unusual pneumonia to the World Health Organization.By January 25th, Beijing, Shanghai,u planting gutter and many other provinces had declared public health emergencies, and most cities in Hubei went into lockdown.During this time span, it was unclear whether the virus was a rumor, how deadly it was, or how it spread.In three studies, we investigate how people in China reacted to COVID-19 during this early window of uncertainty.We find evidence that people in some regions reacted more proactively to this ambiguous threat.We test two broad categories of predictors: objective risk factors and subjective cultural factors.Analyses reveal that culture—not simply objective risk—explains meaningful differences in how people responded.At the onset of the COVID-19 pandemic, our research team observed whether people wore masks in public spaces.Day 0 of our observations was January 23rd, 2020, the day Wuhan went into lockdown.We observed people at eight sites across seven Chinese cities for two weeks.We ended our observations when mask use was nearly universal.However, a limitation to the data was the number of researchers we could deploy quickly and safely.Thus, to supplement the data, we surveyed people from a broader range of provinces on when they started wearing masks.Finally, we triangulated the findings against web searches for “masks,” which are less direct but provide more data points and a complete geographic coverage.

In reviewing previous studies on mask use, we identified three limitations.First, most studies relied solely on self-reported data.This could be problematic as people may feel pressured to report that they wore masks even if they did not—meaning self-reports may not reflects actual mask use.In this study, we measure both self-reports and observed behavior, which allowed us to test whether the results converge.Second, few studies have tracked mask use over time.One notable exception is a Hong Kong study, which found that mask use increased from 12% to 67% during the first seven days of the SARS outbreak.Studying response change over time is crucial as early action can save lives.For example, analyses estimated that implementing COVID-19 measures seven days earlier in the United States could have drastically reduced cases.Third, the few observational studies of mask use we found were limited in the locations and lengths of time tracked.For example, a study of mask use during H1N1 only observed two subway stations in Mexico City.Our study expands on this approach by covering multiple, diverse regions.This richer dataset allows us to explore a range of cultural factors beyond basic demographics like age and gender.We move beyond prior research on masks by testing for less obvious cultural differences that might influence mask use.One feature of collectivistic cultures is interdependence—a view that people are, or should be, dependent on each other.Such a worldview could increase mask use because, even if people are unafraid of risking their own health, masks could prevent them from transmitting the virus to others.Even before the COVID-19 outbreak, some cultural observers argued that wearing masks in Japan symbolized an obligation to protect others from the wearer.In contrast, some people argue that mask mandates infringe on individual freedoms in individualistic cultures like the US.One important study found that mask use was higher in more collectivistic nations and US states that scored higher on collectivism measures.Another cultural influence on mask use could be norm tightness.All societies have social norms—ideas about what behaviors are proper and not.Yet some societies have tighter norms than others.Recent research suggests that tightness varies within China.Specifically, norms are tighter in more developed provinces, as well as provinces that farmed rice in the past.Tight norms come with costs and benefits.Tight societies generally have stricter rules— which seems to conflict with out-of-the-box thinking and innovation.For example, tighter societies have fewer patents for inventions.However, tight norms can help societies respond to danger.Tighter societies tend to have more social order , which might facilitate strict mask policies.