Use Of Firecrackers Research Articles

Trends of air pollution variations during pre-Diwali, Diwali and post-Diwali periods and health risk assessment using HAQI in India

During 2019 to 2022, a comprehensive study was conducted across 71 stations spanning over 15 states in India to investigate air quality variations during the pre-Diwali, Diwali, and post-Diwali periods. The investigation, centred on the extensive use of firecrackers during festive times, revealed a short-term deterioration in air quality with long-lasting impacts. PM2.5 and PM10 levels were found to significantly increase during Diwali and the post-Diwali period compared to the pre-Diwali period. The levels of PM2.5 and PM10 experience respective increases of 44.66% and 11.03%, 29.12% and 05.41%, 52.63% and 23.38%, and 39.65% and 17.61% during Diwali period from 2019 to 2022, where 68.84% and 34.32%, 44.42% and 29.42%, and 48.70% and 25.22% in 2019, 2021 and 2022 in post-Diwali period compared to the pre-Diwali. The Mann–Kendall and Sen's slope analyses reveal statistically significant positive trends (increasing) in both PM10 and PM2.5 levels during the Diwali festival period. Notably, the study introduced the Health Hazard-based Air Quality Index (HAQI), which demonstrated higher values than the National Ambient Air Quality Index (NAAQI). Unlike NAAQI, which considers individual pollutant sub-index values, and considered highest one of sub-index values in AQI analysis. HAQI provides a more comprehensive assessment of health risks associated with exposure to multiple pollutants effects. In 2022, AQI and HAQI values during pre-Diwali were 114 and 146.18, during Diwali were 173 and 332.18, and post-Diwali were 191 and 414.14, respectively. These findings underscore the elevated risk during Diwali and the post-Diwali period due to heightened pollution levels, emphasizing the need for public awareness and potential mitigation strategies. The study calls attention to the importance of considering cumulative health impacts and suggests the adoption of HAQI for more informative air quality assessments.

Effectiveness of safety precaution intervention regarding use of fire crackers on knowledge and fire accidents among school children

Diwali is one such joyous festival which is loved and celebrated by everyone over the country as the festival of lights. It is celebrated by lighting oil lamps and firecrackers like a bomb, flowerpots, chakri, rockets, etc. Firecracker injuries are common in India, of which the majority takes place during diwali. A quasi experimental study was done to assess the effectiveness of safety precaution intervention regarding use of fire crackers on knowledge and fire accidents among school children at Government Middle school, Tiruvannamalai.110 subjects in experimental & 110 subjects in control group were selected by using convenience sampling technique. Post test only design was used. Knowledge and fire accidents were assessed by using questionnaire and observational checklist respectively. The study findings revealed that in control group, the mean posttest score for knowledge was 9.2 whereas in experimental group, the mean score was 18.1 and the calculated t value is 8.5 shows statistically significant at P<0.001 level.The mean score for fire accidents in control group is 4.19 whereas in experimental group mean score was 2.8 and the calculated unpaired t value t=5.5 shows statistically significant at P<0.001 level. The study concluded that safety precaution intervention is necessary to create awareness and control the fire crackers injuries among school children and they are also the message carrier.

Conflict Mitigation Practices and Conservation Awareness of Orangutans: A Case Study from Tangkahan Ecotourism, Leuser Ecosystem, Indonesia

Killing orangutans in human-orangutan conflicts threatens their populations. Individuals with high conservation awareness tend to tolerate orangutans' crop foraging. In our study in Tangkahan ecotourism, Leuser Ecosystem, Indonesia, we examined local community mitigation methods and their understanding of orangutan conservation. We utilized a convenience sampling method for this study, primarily serving as a pilot study to test the questionnaire we had designed. This questionnaire consisted of open-ended questions used in semi-structured interviews. We conducted interviews with 16 respondents, all of whom willingly participated and allowed us to record their responses. Our findings revealed that the most commonly employed mitigation methods by the local community were the use of firecrackers and traditional crop guarding. Notably, these methods were non-lethal in nature, which aligns with the respondents' overall conservation awareness. All participants demonstrated knowledge of the protected status of orangutans, and some provided further insights into their rarity, endangerment, population decline, habitat degradation, and endemism. Their positive attitude likely stems from the impact of ecotourism.

Air Quality Concentration, Transport/Dispersion and pathways of particulate matter during community celebration of Diwali days over Visakhapatnam city

Urbanization, industrialization and consumerization have increased pollution levels in our growing cities. The activities of the people on a mass scale during festivities and celebrations can aggravate the problems of the environment. Diwali is a community festival during which the bursting of crackers and lighting of lamps mark the celebration. The large-scale burning of pyrotechnics effuses large amounts of gaseous chemicals into the surrounding atmosphere and sounds emanating from low-explosive substances can culminate into high-decibel noises. An attempt is made in this study to evaluate the air quality, concentration and pathways of the dispersing substances arising from the bursting crackers at this community celebration in the city of Visakhapatnam. Data on diurnal variations, concentration and ratio of the pollutants, namely PM2.5, PM10, SO2, NO2, CO, ozone, benzene and toluene are gleaned from the CPCB data and vis-a-vis the air quality index was evaluated. The role of meteorological parameters is analyzed and the correlation of meteorological parameters [Temperature (TEMP), Relative Humidity (RH), Wind Speed (WS)] with various pollutants is assayed. Transportation, dispersal and pathways of the pollutants during the study period are depicted through HYSPLIT trajectories. Correlation among the pollutants is also assessed. The study reveals that the use of firecrackers during Diwali is a significant source of particulate matter (PM2.5, PM10) and other gaseous pollutants (SO2, NO2, CO, Ozone, Benzene and Toluene) in the ambient air, thereby impacting urban air quality during the sampling period.

Assessment of air quality in Lucknow, India during the festival of Diwali for four successive years amid the COVID-19 pandemic lockdown

The purpose of this research is to assess the impact of Diwali crackers on air quality in Lucknow, India. The monitoring of PM10, PM2.5, NOX and SOX was carried out in residential areas for Pre-Diwali (Pre-D), Diwali and Post-Diwali (Post-D) during four consecutive years. The variation in average levels of PM2.5, PM10, SO2 and NO2 were recorded during Diwali celebrations of 2019(1.59, 1.51, 1.66 and 1.39), 2020(1.75, 1.65, 1.24 and 1.29), 2021(1.65, 1.56, 1.53 and 1.38) and 2022(1.58, 1.53, 1.45 and 1.42) times higher, respectively than Pre-D. Similarly, during Post-D in 2019(1.21, 1.16, 0.98 and 0.98), 2020(1.18, 1.03, 0.92 and 0.88), 2021(1.15, 1.08, 0.99 and 0.96) and 2022(1.59, 1.07, 1.01 and 0.98) times higher, respectively regarding to Pre-D. The level of PM2.5, PM10, SO2, and NO2 during Diwali were found higher in 2019(1.44, 1.21, 1.52 and 1.37)*, 2020(1.29, 1.12, 1.35 and 1.17)** and 2022(1.38, 1.15, 144 and 1.31) respectively, concerning to 2020. However, AQI level during Pre-D*, Diwali** and Post-D were surges in 2019(23%*, 21%** and 30%), 2021(15%*, 13%** and 16%)** and 2022(20%*, 16%*, and 19%) respectively than 2020, due to burning of firecrackers. However, significant decline in air pollutants (APs) in 2020 was attributed due to controlled use of firecrackers along with restricted anthropogenic activities because of nationwide lockdown. The result indicates, the concentration of APs was significantly increased due to firecrackers during Diwali 2019–2022. This study will be helpful for many policy makers and concerned authorities to proper implementation of pollution management strategies to reduce this phenomenon.

Promotion of eco-friendly Diwali

Abstract Background: Diwali is a major festival in India and is celebrated with great enthusiasm and fervor. Due to bursting of firecrackers on large scale during Diwali releases harmful gases and toxic substances into the atmosphere leading to air pollution. It causes health problems for children, patients, and senior citizens. Objectives: The objective of this study was (1) To assess the knowledge, attitude, and practice of school-going students regarding the use of firecrackers. (2) To determine the prevalence of symptoms related to bursting of firecrackers among students and their families. (3) To find out the association between students' knowledge about health effects of firecrackers and their parents' education. Materials and Methods: An observational, cross-sectional study was done by using self-administered, validated, and pretested pro forma. The study was conducted in all schools located within 250 m2 of distance from the urban health training center of a private medical college. There were three schools falling under these criteria. All 8th standard students (215) of these three schools were included in the study. Results: Out of the total, 77% were boys. Many, i.e. 63% of students burst firecrackers during Diwali. The majority of students, i.e. 67% have knowledge about health effects of firecrackers. The majority, i.e. 80% of students promote eco-friendly Diwali celebration. The use of firecrackers was highly significant among boys (<0.001) and whose parent's education was below graduate level (<0.001). Symptoms of cough (30%), shortness of breath (22%), and eye injuries (3%) were reported due to bursting crackers. Conclusions: Overall knowledge about health effects of crackers was higher among students whose father's education was graduate and above. Thus, students have a positive attitude toward eco-friendly Diwali celebration.

An Efficient Surveillance System to Detect and Prevent Elephant Intrusion in Forest Borders

Now days the conflict takes place between human and elephant is one of the biggest issue throughout the world. In Tamilnadu the biggest elephant conflict arise in villages available near nilgris, muthumalai, etc. Most of the Asian and African countries has farm land, it gets affected by elephants. The crop land are affected by elephants it is one of the biggest issue throughout the world. There some traditional methods like use of fire crackers, drum beating, construction of elephant barriers, noise-making, fencing etc. are used so far. But these methods are not effective in all the situation to prevent the crop as well as human from elephants. The proposed system is more efficient and accurate than the other systems. The vibration sensor is used to detect the movement of elephant in forest border areas. The elephant is captured through camera. The animal is found out of camera zone it is detected through the sound produced by elephant. The captured image is send to database and the SMS is sent to nearby forest officers, crop field owner and also public people. The SURF algorithm is used to match the captured image with database. Likewise audio finger print algorithm is used to detect the algorithm through voice command. Here ZigBee is used to transmit the SMS to 25 meter around the forest areas.

Numerical simulations of different sectoral contributions to post monsoon pollution over Delhi

The National Capital Region (NCR) of India, Delhi, has experienced high post-monsoon pollution along with several peak pollution episodes in recent years. Diwali, the festival of lights, which is among the biggest festivals of India celebrated during the post-monsoon season, is also considered a pollution event associated as it is with the lighting of a large number of firecrackers. 2016 Diwali pollution episode continued for a week creating severe discomfort to residents of Delhi, prompting the judiciary to ban the sale and use of firecrackers in Delhi from 2017 onwards. The current study analyzes different sectoral and temporal emissions contribution to the 2016 post monsoonal pollution episode over Delhi using a fully coupled chemical transport model. The findings of the study indicate that aerosols produced from crop residue open burning at the northwestern states contributed more than 60% of the total simulated surface concentration during the period under study. Model experimental simulations show that despite emissions from within the city, what explains the severity of pollution over Delhi during the period under consideration is an additional pollution load emanating from these intense crop open burning sessions from nearby areas. Further, model simulations show that while Diwali emissions can elevate the pollution load over Delhi, the effects do not last beyond 48 h. It is found that the stagnation of the pollutants several days beyond the 2016 Diwali day was due to favorable meteorological conditions like low surface temperature, lower boundary layer height, and weak northwesterly winds. The study shows that in order to improve air quality in Delhi during the post-monsoon period, mitigation efforts should target the adjacent rural areas, especially when there is massive burning of crop residue in those areas.

Profile of firecracker injuries of the eye during Diwali: A tertiary eye-care center study

Aims and Objectives: The aim was to study the demographic pattern, clinical features, management, and prognosis of the patients with firecracker-related ocular injuries during Diwali. Materials and Methods: This institution-based prospective study was done in 30 patients who attended eye emergency and outpatient department (OPD) of Calcutta National Medical College and Hospital, West Bengal, during the period of 1 week of Diwali in 2016 and 2017. The parameters studied were the age and sex of the patients, type of firework (crackers and sparklers), eye involved, severity of injury with respect to active and passive participants, management, severity of injury, and visual outcome with respect to type of firecrackers. Results: A total of 30 patients attended eye OPD and emergency during our study period, of which 23 (76.7%) were male and 7 (23.3%) were female. All of them were in the pediatric age group (1–15). All patients were examined on the day of injury. Patients between 6 and 10 years of age were most commonly affected. Four cases (13.3%) were open-globe injuries and 26 (86.7%) cases were closed-globe injuries. Visual acuity varied from 6/9 to no perception of light. The most common firework involved was the crackers. Conclusions: Careless and indiscriminate use of firecrackers may sometimes lead to serious ocular damage. In India, use of fireworks is quite common during various festivals, particularly during Diwali, thus fireworks-related ocular injuries are important causes of blindness. This prospective study revealed the presentation and outcome of ocular injuries due to firecrackers in this area of mixed culture during this festive week.

Epidemiology of the last Wednesday Eve Festival injuries in East Azerbaijan Province, Iran

Iranian people have been celebrating the last Wednesday Eve Festival (Chaharshanbeh Soori) from Zoroastrian tradition (1725 BC). This ceremony, which had previously comprised a wide range of socially pleasant and well-accepted traditions, has now been changed into a scene of horror and danger by fireworks that threaten the physical, mental and social health of the community. Purpose: The purpose of this study was to investigate the epidemiological aspects of injuries due to Chaharshanbeh Soori in East Azerbaijan Province, Iran. Methods: This is a descriptive epidemiological study. Data on injuries caused by Chaharshanbeh Soori events were collected by using a national questionnaire in the emergency words of all public and private hospitals from March 15 to April 15, 2018. In this study, demographic and epidemiological variables including age, sex, education, the position of the injured person, living area, injured organ, the type of injury, and outcome of the injury were collected. Data were analyzed using Excel 2013 software for descriptive statistics. Results: A total of 318 injured people have been registered (incidence rate of 9 per 100,000 population). 80% of them were male and 20% were female. 53.8% of the injured people were under 20 years of age. 90% of the injured lived in urban areas, 7% in rural areas and 3% in suburban areas. 65% of injuries occurred during the use of firecrackers, 32% occurred for whom watching or passing, and 3% occurred during the construction of firecracker. 62% were uneducated or under diploma, 29% had diplomas or associate degree, and 9% had a bachelor or master degree. In terms of the type of injury, 57% suffered burns, and 43% had cuts or wounds. In total 289 outpatients were treated as outpatients, 28 were hospitalized as inpatients, one led to disability and death was not reported. Conclusion: Considering that most injuries are made by urban boys under the age of 20 who use the firecrackers as a means of happiness, effective interventional planning for them and their parents is necessary by health and safety officials of the community using the (successful and unsuccessful) past experiences.

Automated Elephant Entry Prevention for Human and Crop Protection

Farming in areas with elephants has been the norm in many parts of Asia for thousands of years. In particular, farmers have settled closer to areas where elephants are present and started growing crops. Elephant raids occur in the night time where people do not notice the presence of an elephant until it starts an offensive behavior. Such raids damage the crops, harvest storages and homes in addition to causing deaths of humans. A multitude of traditional methods have been developed through the ages to reduce and prevent crop raiding by elephants like shouting, drum-beating, noise-making, use of fire crackers, electric fencing, lights and torches. Such activities may also indicate to elephants that their presence is detected, and that they have to contend with aggressive humans. In the proposed system, automated detection of the presence of elephant is done by analyzing the infrasonic sounds produced by elephants and they are prevented from entering into farms by propagating the offensive sounds in low frequencies without human intervention.

Consumers of Fireworks and Pollution in India : Implications for Marketers and State Policy

There are a number of festivals celebrated throughout India. Amongst all, religious festivals like Diwali, Dusshera etc find special mention. These festivals are marked by the usage of bright lights and firecrackers which cause pollution. The unintended consequence of this is an increase in the pollution level. The enthusiasm of the consumer during festivals becomes all the more buoyant on account of promotion by marketers. The pollution level as a result of the use of firecrackers during these festivals has acquired dangerous proportions especially in metros like Delhi. In 2016, a number of festivals were concentrated in the month of October. Coincidentally, AQI of Delhi jumped from the figure of 160 to 389 from September 30th to November 1st depicting a huge fall in its air quality. The present paper aimed at exploring the use of firecrackers during festivals and analysing the stakes of three major parties-the consumers, marketers and state. The paper suggests the need for a change in the way festivals are celebrated by changing the perception of consumers. It also recommends a need for more ethically responsible behaviour on the part of marketers as well as the state to control the ill effects of using firecrackers.

Short-Term Introduction of Air Pollutants from Fireworks During Diwali in Rural Palwal, Haryana, India: A Case Study

The contribution of firework-related air pollutants into the rural atmosphere was monitored by measuring ambient air concentrations of PM2.5, CO, and metals over Mitrol– Aurangabad, Haryana, India, before, during, and after the 2015 Diwali celebration. PM2.5 concentrations were observed to be approximately 5 times and 12 times higher than Indian and WHO 24-h standards, respectively. CO concentrations on the day of Diwali were found to be nearly 7.5 times and nearly 1.5 times higher than Indian standards and WHO 8-h standards, respectively. Increased concentrations of SO4, K, N3, Al, and Na were observed. SO4, K, N3, Al, and Na were found between approximately 2 and 5 times higher on festival days than on a normal, non-festival day in November. Use of firecrackers during Diwali and surrounding celebrations thus contribute to decreased air quality and elevated levels of air pollutants associated with adverse health impacts. Optimization or controlled use of firecrackers during Diwali is suggested in rural areas.

Spectral-domain optical coherence tomography in choroidal rupture following firecracker injury

In India, firecrackers are an integral and essential part of the celebrations. Injuries from firecrackers can lead to serious and irreparable visual damage. We report a case of choroidal rupture following injury caused by firecracker and correlate its optical coherence tomography findings. As ocular firecracker injuries result in significant morbidity, public education regarding proper use of firecrackers may help in reducing the incidence of ocular injuries.

Penetrating trauma of the face and facial skeleton - a case series of six patients.

Penetrating traumas of the facial skeleton are relatively rare; however, they can be dangerous and even life-threatening. The epidemiology of facial skeleton trauma is diverse and depends on the affected region, age, and the kind of foreign body that caused the injury. In Poland, the most common cause of penetrating traumas are accidents and assaults, and only rarely accidents are related to improper use of firecrackers or fireworks. The aim of this study is to present a literature review and our own experience with penetrating traumas of the face and the facial part of the cranium. Six cases with severe wounds and fractures of the facial skeleton were treated between the years 2000 and 2012 in our department. The applied treatment methods depended mainly on the general condition of the patients. In all cases, we achieved acceptable functional and aesthetic outcomes.

Consumers of Fireworks and Pollution in India: Implications for Marketers and State Policy

There are a number of festivals celebrated throughout India. Amongst all, religious festivals like Diwali, Dusshera etc find special mention. These festivals are marked by the usage of bright lights and firecrackers which cause pollution. The unintended consequence of this is an increase in the pollution level. The enthusiasm of the consumer during festivals becomes all the more buoyant on account of promotion by marketers. The pollution level as a result of the use of firecrackers during these festivals has acquired dangerous proportions especially in metros like Delhi. In 2016, a number of festivals were concentrated in the month of October. Coincidentally, AQI of Delhi jumped from the figure of 160 to 389 from September 30th to November 1st depicting a huge fall in its air quality. The present paper aimed at exploring the use of firecrackers during festivals and analysing the stakes of three major parties-the consumers, marketers and state. The paper suggests the need for a change in the way festivals are celebrated by changing the perception of consumers. It also recommends a need for more ethically responsible behaviour on the part of marketers as well as the state to control the ill effects of using firecrackers.

Appraising the spectrum of firework trauma and the related laws during Diwali in North India.

Purpose:To evaluate the epidemiological characteristics and outcomes of ocular injuries resulting from the use of firecrackers during the Diwali festival in all age groups.Materials and Methods:A single-center, retrospective, hospital-based case series presenting with ocular trauma consequent to fireworks usage in a tertiary eye care center in North India during the 5 days of Diwali festival from 2011 to 2015 was conducted.Results:A total of 53 eyes of 45 patients were included in the study, out of which the vast majority (39/87%) were males. The mean age was 20.55 years. Almost an equal number of bystanders (25/55.5%) were affected as compared to people handling the fireworks (20/44.44%). Five (9.43%) eyes had open-globe injury, whereas 48 (90.56%) eyes had closed-globe injury. Eighteen (33.96%) eyes underwent surgical intervention. Thirty-three (62.26%) eyes had final vision >20/200 with eight (15.09%) eyes being vision <3/60 in the affected eye.Conclusion:Firework-related ocular trauma can lead to serious visual impairment. Mandatory legislative laws pertaining to the manufacture, sale, and use of fireworks and creating public awareness can reduce the incidence of this preventable cause of blindness in the society. Initiating new policies for retailers involved in sale of these firecrackers can also bring in decrease of such morbidities.

Role of long-range transport and local meteorology in seasonal variation of surface ozone and its precursors at an urban site in India

This study is based on the continuous measurements of ozone (O3), carbon monoxide (CO) and nitrogen oxides (NOx) at a semi-arid urban site in Udaipur, India during the years 2011–2012. The mixing ratios of trace gases show strong and weak diurnal variations during the winter and monsoon seasons, respectively. The temporal changes in local emission and PBL depth play an important role in the diurnal variation of trace gases. The daily means of O3, CO and NOx were in the ranges of 5–53 ppbv, 121–842 ppbv and 3–29 ppbv, respectively. The mixing ratios of trace gases were highest and lowest during the winter/pre-monsoon and monsoon seasons, respectively. In the winter season, the lowest of O3 during night–morning hours was caused by the efficient loss due to titration and deposition compared to other seasons. During the winter to the pre-monsoon period, higher levels of trace gases were due to regional biomass burning and long-range transport of continental pollutants. However, strong convection, rainfall and transport of oceanic air resulted in the lowest concentrations of trace gases during the monsoon season. The O3min values tend to increase slightly with increasing values of Tmin while COmax and NOxmax decrease rapidly with increasing values of Tmin. The levels of CO and NOx decreased with increasing wind speed, while O3 tends to increase with wind speed. The rates of change of O3 (dO3/dt) were about 3.7 ppbv h−1 and −4.5 ppbv h−1 during the morning and evening hours, respectively. Exceptionally high levels of trace gases during the Diwali (festival) period were due to extensive use of firecrackers from evening till morning hours. The enhancements of O3, CO and NOx compared to normal days were about 61%, 62% and 23%, respectively.

Crash and Burn: Ocular Injuries due to Fireworks

Purpose: To identify the patterns of ocular injury and to determine ocular morbidity resulting from the use of firecrackers. Methods: A prospective observational study of all patients presenting with ocular trauma consequent to fireworks usage in a tertiary eye care center in South India over a one-month period around the autumn festival of Diwali. We also reviewed the published literature from around the world reporting ocular injuries due to firecrackers. Result: 49 patients were included in the study, out of which the vast majority (40/81%) were males. The mean age was 17 years. Almost an equal number of bystanders (24/48.9%) was affected as compared to people handling the fireworks (25/51%). 13 (26.53%) patients had open-globe injury whereas 33 (67.34%) patients had closed-globe injury. Twenty-two (44.8%) patients underwent surgical intervention. Eighteen (36.7%) patients had final vision less then 20/40 (range = 20/50 to No Perception of Light) with eight patients having no perception of light in the affected eye. Conclusion: Unregulated use of firecrackers can lead to significant ocular morbidity, mainly involving children, young males, and even innocent bystanders. A combination of public awareness and appropriate legislative laws should be formulated regarding the use of fireworks to decrease the load of needless blindness on society.

Ambient Air Quality during Diwali Festival over Kolkata - A Mega-City in India

The effects of fireworks on air quality was assessed from the ambient concentrations of PM10, water soluble ionic species, metals and SO2 over Kolkata metropolis, India during Diwali festival in November 2010. PM10 concentrations on Diwali night were found to be ~5 times higher than the normal day night-time average. The increase in night-time concentrations of the metals on Diwali night spanned over a wide range (Al, Zn, Pb and Cd showed 5-12 times increases, Cu, Fe and Mn showed 25-40 times and Co and V showed 70-80 times) compared to normal night-time concentrations. The water soluble ionic species showed 1.5-6 times higher concentrations on Diwali night than on normal days. The most significant increases were found for K^+, Ca^2+, Mg^2+ and SO4^2-. The diurnal variations in PM10 and SO2 were also studied at one of the sites, and the results showed that their maximum concentrations were on Diwali night between 8 P.M.-3 A.M., indicating maximum firework activities during this period. PM10 and SO2 concentrations increased by ~5 times compared to those on normal days during this period at this site. The extensive use of firecrackers during Diwali festival thus leads to significant increases in these air pollutants, and since they are associated with serious, adverse health impacts, the use of fireworks during in this kind of festival in a highly populated city, like Kolkata, India, needs to be controlled.