Influence Of Wind Direction Research Articles

Environmental impact assessment of Pinaceae airborne pollen and green infrastructure using BIM

Abstract Urban air quality is a parameter that plays a major role in human health at the local scale. Consequently, in urban planning, the behavior and potential risk of allergenicity for some pollen grains coming from ornamental trees and green spaces surrounding newly built buildings, should be considered. This paper aims to study how pollen exposure, influenced by weather parameters, can be assessed and integrated in the designing and building of constructions as other component of air quality assessment beforehand, by using BIM. Based on a comparative aerobiological study at the height over a building (sampled by two traps at ground and at 16 m), a 3D local dynamic parametric scenario was modelled using BIM, and hourly average Pinaceae pollen concentrations (due to the closeness of pine trees to the samplers). From continuous recording (2009–2011) influenced by height and the influence of wind direction and speed was analysed. Additionally, a map of pine trees geolocated around the studied building was produced and the hourly average Pinaceae pollen concentrations were represented by Revit. BIM together with aerobiology can be a novel and useful tool for the construction of buildings considering airborne biological particles. This represents a first step towards the integration of some unusual environmental parameters in urban planning. Pollen grains modelling as an environmental health criterion for the construction of new buildings will allow technicians to avoid possible future isolation points in the design of building envelopes, and high pollen exposure rates could be avoided, creating ‘allergy-free’ buildings.

Influence of Wind Direction on Thermodynamic Properties and Arctic Mixed‐Phase Clouds in Autumn at Utqiaġvik, Alaska

Seven years of autumnal ground‐based observations (September–November 2002–2008) at the U.S. Department of Energy Atmospheric Radiation Measurement North Slope of Alaska site have been analyzed for addressing the occurrence frequency and macrophysical and microphysical properties of Arctic mixed‐phase clouds (AMC), as well as the relationship between environmental parameters and AMC properties. In September and October, AMC occurrence frequency is 20–30% lower during a southerly wind when compared to the other wind directions; in November, the variation of AMC occurrence frequency with wind direction is small. The mean liquid water path in November is about half of that in October and September. When the surface is snow free, temperature (T) and specific humidity (q) profiles during a northerly wind are warmer and moister than those for the southerly wind. Northerly wind profiles have a higher relative humidity to ice (RHi) and lower atmosphere stability. Furthermore, the AMC occurrence frequency has a positive relationship with RHi and a negative relationship with stability. These two points may explain the lower AMC occurrence frequency during a southerly wind. During a northerly wind, AMCs have larger radar reflectivity, wider spectrum width, and larger Doppler velocity signatures. The stronger precipitation for AMC during a northerly wind is possibly due to the cleaner air masses from the ocean (north). With the same amount of q, the radar spectrum width has a higher frequency in the larger bins during a northerly wind. Both T, q, and radar reflectivity, radar spectrum width profiles show evidence of deposition in the sub‐cloud layer in September and October.

Environmental Determinants of Malaria Transmission Around the Koka Reservoir in Ethiopia.

New dam construction is known to exacerbate malaria transmission in Africa as the vectors of malaria—Anopheles mosquitoes—use bodies of water as breeding sites. Precise environmental mechanisms of how reservoirs exacerbate malaria transmission are yet to be identified. Understanding of these mechanisms should lead to a better assessment of the impacts of dam construction and to new prevention strategies. Combining extensive multiyear field surveys around the Koka Reservoir in Ethiopia and rigorous model development and simulation studies, environmental mechanisms of malaria transmission around the reservoir were examined. Most comprehensive and detailed malaria transmission model, Hydrology, Entomology, and Malaria Transmission Simulator, was applied to a village adjacent to the reservoir. Significant contributions to the dynamics of malaria transmission are shaped by wind profile, marginal pools, temperature, and shoreline locations. Wind speed and wind direction influence Anopheles populations and malaria transmission during the major and secondary mosquito seasons. During the secondary mosquito season, a noticeable influence was also attributed to marginal pools. Temperature was found to play an important role, not so much in Anopheles population dynamics, but in malaria transmission dynamics. Change in shoreline locations drives malaria transmission dynamics, with closer shoreline locations to the village making malaria transmission more likely. Identified environmental mechanisms help in predicting malaria transmission seasons and in developing village relocation strategies upon dam construction to minimize the risk of malaria.

Predicting Dispersion and Pollutant Concentration of Dimethyl Sulfide (DMS) from a Biofilter Under Various Atmospheric Conditions

Meat rendering plants convert waste animal materials into value added products. During the conversion process, several highly odorous compounds such as ammonia, ethylamines, hydrogen sulfide, dimethyl sulfide, and methyl mercaptan are released into the atmosphere. Due to odorous nature, these compounds cause nuisance to the community who live in the neighborhood of the meat rendering plant; thus, plant received regular odor complaints. Although installation of gas-phase biofilters alleviates the problem of odor complaints, the successful operation of a biofilter depends on many parameters such as maintaining optimum moisture content of the biofilter media, sufficient empty bed residence time (EBRT), high surface area for mass transfer, acceptable mechanical resistance to avoid bed compaction, and good environment for bacterial growth. Deficiencies in the operational parameters of a biofilter can lead to high level of pollutant release into the environment. In this work, dispersion of pollutants that are released from an industrial biofilter, installed in Ontario, Canada, is investigated. Dispersion model CALPUFF was used to predict pollutant concentrations and dispersion under various atmospheric conditions. Influence of wind directions, plume paths, atmospheric conditions, and removal efficiency of the biofilter are investigated.

Exposure assessment of particulate matter and blood chromium levels in people living near a cement plant.

This study evaluates the effect of air pollution caused by cement plants on nearby residential areas and performs an exposure assessment of particulate matter (PM) and total Cr, Cr6+, Pb, and Al. Further, the blood Cr levels of residents exposed to PM released by cement plants are also assessed. Nine buildings (eight residential and one elementary school building) close to cement plants were selected for this study, which were located in Pyeongtaek port, in west of Gyeonggi Province, South Korea. A total of 51 suspended particulate samples were collected at a flow rate of 2.0L/min. Total Cr was more widely detected in residents' houses and elementary schools. PM levels were higher at distances of 4.1 and 4.8km than those at closer distances of 2.7km. This was due to the influence of wind direction. The estimated mean blood level of Cr for the study participants was 3.80μg/L, which is higher than levels estimated by other studies on Cr blood levels. Therefore, cement plants could cause an increase in total Cr and blood Cr levels in residential areas, and more continuous monitoring is necessary to better understand their impacts.

Scalar Fluxes Near a Tall Building in an Aligned Array of Rectangular Buildings

Scalar dispersion from ground-level sources in arrays of buildings is investigated using wind-tunnel measurements and large-eddy simulation (LES). An array of uniform-height buildings of equal dimensions and an array with an additional single tall building (wind tunnel) or a periodically repeated tall building (LES) are considered. The buildings in the array are aligned and form long streets. The sensitivity of the dispersion pattern to small changes in wind direction is demonstrated. Vertical scalar fluxes are decomposed into the advective and turbulent parts and the influences of wind direction and of the presence of the tall building on the scalar flux components are evaluated. In the uniform-height array turbulent scalar fluxes are dominant, whereas the tall building produces an increase of the magnitude of advective scalar fluxes that yields the largest component. The presence of the tall building causes either an increase or a decrease to the total vertical scalar flux depending on the position of the source with respect to the tall building. The results of the simulations can be used to develop parametrizations for street-canyon dispersion models and enhance their capabilities in areas with tall buildings.

A Study of Wind Direction Effects on Sea Surface Specular Scattering for GNSS-R Applications

A modeling study investigating the influence of wind direction on spaceborne global navigation satellite system reflectometry (GNSS-R) near-specular observations of the sea surface is reported. The study first focuses on a purely specular geometry under plane wave incidence, for which it is shown using the theorem of reciprocity and reflection symmetry that up-down wind variations are identically zero. It is also shown that “single-scattering” approximations of rough surface scattering predict no variations with wind direction of any kind for a purely specular geometry, while higher order approximations (such as the second-order small-slope approximation) can predict up/cross wind differences. Examples of these variations are reported and found to be small. Because the delay doppler maps (DDMs) measured in GNSS-R include some nonspecular contributions even for “specular” portions of the DDM, the second part of the study performs an examination of near-specular DDM variations with wind direction using the widely used geometrical optics approximation of surface scattering for a surface described with the non-Gaussian Cox–Munk slope probability density function. Variations with wind direction of the normalized radar cross section (NRCS) mapped onto the surface are examined, and again, it is shown that these variations are small for surface portions contributing to the near-specular portion of the DDM. In addition, it is shown that the dependencies of the bistatic NRCS on wind direction are such that differing portions of the surface “glistening zone” have differing phase shifts in their dependence on wind direction, causing the wind dependencies of the final near-specular DDM to be negligible. The final results of the study suggest that any wind direction dependence in spaceborne GNSS-R should be sought only in portions of the DDM away from the specular region. These results provide information to guide analyses of the wind direction information available in current GNSS-R missions such as TDS-1 and Cyclone Global Navigation Satellite System.

Multivariate statistical analyses of air pollutants and meteorology in Chicago during summers 2010-2012

Aerosol, trace gas, and meteorological data were collected in Chicago, Illinois during 2010–2012 summer air studies. Ozone, nitrogen oxides, acetate, formate, chloride, nitrate, sulfate, and oxalate concentrations as well as temperature, wind speed, wind direction, and humidity data were explored by both principal component analysis (PCA) and canonical correlation analysis (CCA). Multivariate statistical techniques were applied to uncover existing relationships between meteorology and air pollutant concentrations and also reduce data dimensions. In PCA, principal components (PCs) revealed a relationship of ozone and nitrate concentrations with respect to temperature and humidity, coupled with transport of species from the south in relation to the sampling site (PC1). PC2 was a measure of secondary aerosols but also suggested acetate and formate presence was a result of primary emissions or transport. Both PC3 and PC4 contained residual information with the former representing days of lower pollution and the latter representing northerly wind transport of chloride, nitrate, and ozone to the sampling site. In CCA, three canonical functions were statistically significant. The first indicated high temperature and low wind speed had a strong linear relationship ozone, oxalate, and nitrogen oxide concentrations whereas the second function showed a strong influence of wind direction on acetate, formate, and chloride concentrations. Residuals of temperature, wind speed, trace gases, and oxalate also were in the second function. The only new information in the third function was humidity. Overall, PCA and CCA bring forth multivariable relationships, not represented in descriptive statistics, useful in understanding pollution variability.

The Impact of Meteorological Factors on PM2.5 Variations in Hong Kong

This paper aims to explore the impact of meteorological factors on PM2.5 concentrations in Hong Kong. The PM2.5 and meteorology data including temperature, pressure, rainfall, relative humidity (RH), wind speed and wind direction from January to December of 2013 were collected. The correlation analysis between PM2.5 and meteorological factors were conducted for each month and season. The meteorology data were classified into several intervals and the mean PM2.5 concentrations for each interval were calculated to see the tendency. According to the correlation analysis results, the PM2.5 concentrations have a positive relationship with pressure with correlation coefficients 0.507 while have negative relationships with temperature, RH, rainfall, wind speed with correlation coefficients -0.512, -0.237, -0.524, -0.284, respectively. In addition, the wind direction influence PM2.5 concentrations through affecting the spreading direction of PM2.5. The north wind in winter increased the PM2.5 in Hong Kong while the south wind in summer decrease the PM2.5. Therefore, the meteorological factors affect the aggregation, diffusion, spread of PM2.5. They have a leading impact on PM2.5 concentrations when the domestic emission stays stable.

Ground Deposition and Airborne Spray Drift Assessment in Vineyard and Orchard: The Influence of Environmental Variables and Sprayer Settings

Spray drift assessment encompasses classification of the capacity of each sprayer/technology/setting combination to reduce or avoid the spray drift risk, as well as drift measurement to define buffer zones mandated during pesticide application. Compounding the challenge of these tasks is the great variability of field evaluation results from environmental conditions, spray application technology, canopy structure, and measurement procedures. This study, performed in Spanish context, evaluates the effects of different parameters on comparative measurements of ground and airborne spray drift employing the ISO22866:2005 protocol. Four configurations of air blast sprayers, derived from two fan airflow rates and two nozzle types (conventional and air-induction), were tested in orchard and vineyard at late growth stage. Spray drift curves were obtained, from which corresponding Drift Values (DVs) were calculated using an approximation of definite integral. Both sprayer settings and environmental variables statistically affect spray drift total amounts and result variability. PCA analysis showed that nozzle type and wind speed characteristics explained 51% and 24% of the variance, respectively. In particular, mean wind direction influence ground sediments (Pr < 0.01) and maximum wind speed strongly influence airborne drift value (Pr < 0.0001). The wind characteristics concealed the influence of adopted fan airflow rates on final spray drift assessment results. The effect of uncontrollable environmental conditions makes objective and comparative tests difficult.

A micro-climatic study on cooling effect of an urban park in a hot and humid climate

The cooling effect of a 4.5ha urban forest park located in a dense city center area in a hot and humid climate was investigated with the three-dimensional microclimate simulation tool ENVI-met v3.1. Dynamic predictions are firstly performed with different wind directions (northerly, southerly, easterly and westerly) for a typical summer day. Then the meteorological data were averaged to eliminate the effect of wind direction, considering equal probability for each wind direction. Overall, when wind speed is 1.5m/s, park cool island (PCI) intensity is about 2°C and the PCI center is offset from the park center if a preponderant prevailing wind direction exists. After eliminating the influence of wind direction by considering equal probability for each wind direction, PCI intensity is about 0.8°C and the PCI center is near to the park center. A higher wind speed would lead to a lower PCI intensity and a smaller area of influence. Compared to air temperature, the spatial distributions of mean radiant temperature and relative humidity are not significantly affected by a preponderant prevailing wind direction. And mean radiant temperature was found to be about 30°C lower in shaded areas of the park.

Development of a new significant wave height and dominant wave period parameterization scheme

Ocean waves generally mix with wind waves and swell, of which only wind waves depend on the local wind field. Using 15 years of hourly observational wind-wave data from eight buoys off the northwest coast of the United States (US), the authors develop a new significant wave height (Hs) and dominant wave period (Tp) scheme (termed as WHP) for open oceans. This scheme relies only on the properties that a single atmospheric model can provide:Hs=0.0143U102+0.9626,H*=0.0628T*3/2where U10 is the wind speed at a reference height of 10m, H* is the dimensionless wave height, and T* is the dimensionless wave period. This relation is fitted to U10 values between 4 and 25ms−1. Comparison results show that the WHP scheme gives an almost best performance in predicting Hs and Tp for the open oceans across different regions. In addition to wind speed, considering the influence of wind direction and stability of the air/sea boundary layer is necessary for wind-wave prediction in coastal areas. Data from the Coupled Boundary Layers and Air–Sea Transfer experiment in LOW winds (CBLAST-LOW) and coastal buoys demonstrate that the effects of the wind direction and stability on Hs and Tp are significant for shallow water; with an increase in water depth, such impacts gradually decrease. Parameterizations for coastal wind waves are also investigated in this paper in Eqs. (19)–(31).

Measurement and Analysis of Coastal Waves Along The North Sea Area of China

Abstract Taking advantage of coastal wave environment to carry out scaled ship model test is an effective testing technology for ship performance. In this paper, the method of spectral analysis is adopted to calculate the significant wave height, period, wave spectrum and some other parameters of some places along the North Sea area of China. The measured wave spectrum and the ocean spectrum are handled into non-dimensional form to evaluate their similarity. The influence of wind direction and tide on coastal waves was analyzed. And the results indicate that the coastal wave spectrum is similar to the ocean spectrum under some specific conditions.

Acute exposure to sulfur dioxide and mortality: a case-crossover analysis of power plant emissions

Purpose: Short-term exposure to sulfur dioxide has been associated with mortality; however, most studies have been conducted in metropolitan areas and do not account for point source emissions (e.g., proximity to power plants). During a three-year period, an administratively ordered air quality monitoring program captured sulfur dioxide (SO2) and particulate matter (PM2.5) emissions in communities within close proximity to a coal-fired power plant. This offered a unique opportunity to assess the health impacts in non-urban communities from this point source. Methods: We used a time-stratified case-crossover design to examine the impact of short-term exposure to SO2 on all-cause, respiratory, circulatory, stroke, and COPD mortality. Conditional logistic regression models were adjusted for PM2.5 exposure, daily average temperature, daily average dew point temperature, weekdays vs. weekends, and holidays. We assessed the influence of wind direction and peak exposures on mortality. Results: 4,693 deaths were included in our analysis. A one-unit increase in SO2 on the preceding day was associated with an increased risk in all-cause mortality [OR=1.03 (95% CI: 1.004,1.06)] and circulatory mortality [OR=1.05 (95% CI: 1.004,1.09)] during the summer season. However, after restricting the analysis to days when the wind trajectory blew from the power plant to impacted communities, SO2 exposure on the day of death and preceding day were significantly associated with all-cause, circulatory, respiratory, and stroke mortality during spring, summer, and winter. Persons over age 65 were more susceptible to these effects than those 65 and under. Conclusions: Communities in non-urban and rural areas can sustain significant health impacts from point source emissions of SO2, such as coal-fired power plants. Epidemiology studies of such sources should account for meteorological conditions, including wind direction.

Impact of meteorological conditions on airborne fine particle composition and secondary pollutant characteristics in urban area during winter-time

The assessment of airborne fine particle composition and secondary pollutant characteristics in the case of Augsburg, Germany, during winter (31 January–12 March 2010) is studied on the basis of aerosol mass spectrometry (3 non-refractory components and organic matter, 3 positive matrix factorizations (PMF) factors), particle size distributions (PSD, 5 size modes, 5 PMF factors), further air pollutant mass concentrations (7 gases and VOC, black carbon, PM10, PM2.5) and meteorological measurements, including mixing layer height (MLH), with one-hourly temporal resolution. Data were subjectively assigned to 10 temporal phases which are characterised by different meteorological influences and air pollutant concentrations. In each phase hierarchical clustering analysis with the Ward method was applied to the correlations of air pollutants, PM components, PM source contributions and PSD modes and correlations of these data with all meteorological parameters. This analysis resulted in different degrees of sensitivities of these air pollutant data to single meteorological parameters. It is generally found that wind speed (negatively), MLH (negatively), relative humidity (positively) and wind direction influence primary pollutant and accumulation mode particle (size range 100–500 nm) concentrations. Temperature (negatively), absolute humidity (negatively) and also relative humidity (positively) are relevant for secondary compounds of PM and particle (PM2.5, PM10) mass concentrations. NO, nucleation and Aitken mode particle and the fresh traffic aerosol concentrations are only weakly dependent on meteorological parameters and thus are driven by emissions. These daily variation data analyses provide new, detailed meteorological influences on air pollutant data with the focus on fine particle composition and secondary pollutant characteristics and can explain major parts of certain PM component and gaseous pollutant exposure.

Influence of wind direction and speed on the transport of particle-bound PAHs in a roadway environment

The influence of wind direction and speed on the transport of vehicular air pollutants was investigated using a mobile laboratory in an urban area. We considered three spatial scales covering typical transport phenomena observed in urban areas: micro-scale (a few tens of meters), middle-scale (a few hundred meters) and neighborhood-scale (a few kilometers). Particle-bound polycyclic aromatic hydrocarbons (PAHs) were selected as an indicator of vehicle emissions in the roadway environment. From the micro-scale measurements, we found a significant difference in the concentration of particle-bound PAHs within a small spatial area, on a two-way road, due to the effect of wind direction when the prevailing wind direction was constant. In the middle-scale experiments, an exponential decrease in the concentration of particle-bound PAHs was observed with distance from the intersection in the direction of the prevailing wind, which is consistent with the results of previous studies. The concentration of particle-bound PAHs near the road was ∼10 times higher than that at 200 m away from the road due to the significantly low background concentration, indicating that particle-bound PAHs are a good indicator of vehicle emissions in a roadway environment. From long-distance (∼15 km) traveling measurements made over 14 days, we found that the average concentration of particle-bound PAHs on the road decreased as the prevailing wind speed increased at the neighborhood-scale, when the wind speed was higher than 2.0 m/s. This analysis, over three spatial scales, will be helpful in understanding the effect of wind on air pollution in a roadway environment in urban areas.

Optimum layout design of onshore wind farms considering stochastic loading

Renewable energy technologies are developing rapidly, while in the last decade great interest is encountered in the use of wind energy, especially due to the energy crisis and serious environmental problems appeared from the use of fossil fuels and therefore a large number of wind farms have been installed around the world. On the other hand the ability of nature inspired algorithms to efficiently handle combinatorial optimization problems was proved by their successful implementation in many fields of engineering sciences. In this study, a new problem formulation for the optimum layout design of onshore wind farms is presented, where the wind load is implemented using stochastic fields. For this purpose, a metaheuristic search algorithm based on a discrete variant of the harmony search method is used for solving the problem at hand. The farm layout problem is by nature a constrained optimization problem, and the contribution of the wake effects is significant; therefore, in two formulations presented in this study the influence of wind direction is also taken into account and compared with the scenario that the wake effect is ignored. The results of this study proved the applicability of the proposed formulations and the efficiency of combining metaheuristic optimization with stochastic wind loading for dealing with the problem of optimal layout design of wind farms.

Joint distribution of wind speed and direction in the context of field measurement

The joint distribution of wind speed and wind direction at a bridge site is vital to the estimation of the basic wind speed, and hence to the wind-induced vibration analysis of long-span bridges. Instead of the conventional way relying on the weather stations, this study proposed an alternate approach to obtain the original records of wind speed and the corresponding directions based on field measurement supported by the Structural Health Monitoring System (SHMS). Specifically, SHMS of Sutong Cable-stayed Bridge (SCB) is utilized to study the basic wind speed with directional information. Four anemometers are installed in the SHMS of SCB: upstream and downstream of the main deck center, top of the north and south tower respectively. Using the recorded wind data from SHMS, the joint distribution of wind speed and direction is investigated based on statistical methods, and then the basic wind speeds in 10-year and 100-year recurrence intervals at these four key positions are calculated. Analytical results verify the reliability of the recorded wind data from SHMS, and indicate that the joint probability model for the extreme wind speed at SCB site fits well with the Weibull model. It is shown that the calculated basic wind speed is reduced by considering the influence of wind direction. Compared to the design basic wind speed in the Specification of China, basic wind speed considering the influence of direction or not is much smaller, indicating a high safety coefficient in the design of SCB. The results obtained in this study can provide not only references for further wind-resistance research of SCB, but also improve the understanding of the safety coefficient for wind-resistance design of other engineering structures in the similar area.

Bird movements at rotor heights measured continuously with vertical radar at a Dutch offshore wind farm

Assessing the impacts of avian collisions with wind turbines requires reliable estimates of avian flight intensities and altitudes, to enable accurate estimation of collision rates, avoidance rates and related effects on populations. At sea, obtaining such estimates visually is limited not only by weather conditions but, more importantly, because a high proportion of birds fly at night and at heights above the range of visual observation. We used vertical radar with automated bird‐tracking software to overcome these limitations and obtain data on the magnitude, timing and altitude of local bird movements and seasonal migration measured continuously at a Dutch offshore wind farm. An estimated 1.6 million radar echoes representing individual birds or flocks were recorded crossing the wind farm annually at altitudes between 25 and 115 m (the rotor‐swept zone). The majority of these fluxes consisted of gull species during the day and migrating passerines at night. We demonstrate daily, monthly and seasonal patterns in fluxes at rotor heights and the influence of wind direction on flight intensity. These data are among the first to show the magnitude and variation of low‐altitude flight activity across the North Sea, and are valuable for assessing the consequences of developments such as offshore wind farms for birds.

Maize pollen deposition in relation to distance from the nearest pollen source under common cultivation - results of 10 years of monitoring (2001 to 2010)

Abstract Background Information on pollen dispersal is essential for the risk assessment and management of genetically modified organisms (GMOs) such as Bt maize. We analyzed data on maize pollen deposition at 216 sites in Germany, Switzerland, and Belgium from 2001 to 2010. All data were collected using the same standardized sampling method. The distances between sampling site and the nearest maize field ranged from within the field to 4.45 km. Results Maize pollen deposition was negatively correlated with distance from the nearest pollen source. The highest pollen deposition was within the field, but depositions of several thousand pollen grains per square meter were recorded over the kilometer range. A power function model most accurately described the relationship between deposition and distance from the nearest pollen source, rather than the exponential model currently used in EU risk assessment and management, which underestimates exposure for distances greater than 10 m. Regression analysis confirmed the high significance of the power relationship. The large variation in pollen deposition at a given distance reflected the influences of wind direction and other meteorological and site conditions. Plausible variations of single values and the predicted mean pollen count at a given distance were expressed by confidence intervals. Conclusions The model described here allows estimations of pollen deposition in relation to distance from the nearest field; therefore, it will be valuable for the risk assessment and management of GMOs. Our results indicate that buffer zones in the kilometer range are required to prevent harmful exposure of non-target organisms to GMOs.