Sci 7.7 Air Quality in Hong Kong (OCR, 2024)

v Flipped classroom The photo below was taken in Hong Kong on a certain day. Do you Wh av E) know why the city seems to be covered in haze™? and answer & the question...

v Flipped classroom The photo below was taken in Hong Kong on a certain day. Do you Wh av E) know why the city seems to be covered in haze™? and answer & the questions. SES » As The photo in Let’s begin was taken on a day when the air quality” in Hong Kong was bad. Air pollution” is an environmental problem in Hong Kong, as well as many other cities around the world. Sulphur dioxide, nitrogen oxides”, ozone”, carbon monoxide and suspended particulates” are some of the major air pollutants™. They are mainly produced during the burning of fossil fuels in power stations, factories and motor cars. Fig 7.36 (a) Power stations, (b) factories and (c) motor cars are major sources of air pollution \ \ - ' \ ya Slbrorrrsavenvrtssnssans as TI I III or I IID II TT Ter EE AT TL air quality ZfE% air pollution ZEF)54 sulphur dioxide Z# {tf nitrogen oxides BAL) suspended particulate #&/ZRF air pollutant Z2A5  Air quality Air pollutants can cause harm to different parts of our body, leading to various health problems. Some of their harmful effects are shown below. @ Learn more about Harmful effects of air pollutants the harmful effects of air pollutants on the Brain Internet. Eyes Carbon monoxide reduces Sulphur dioxide, nitrogen oxides the oxygen-carrying ability air pollutant chp (£@% and ozone irritate eyes of blood, causing dizziness* and headaches Breathing system Sulphur dioxide, nitrogen oxides, ozone and suspended particulates * irritate throat, airways and lungs * worsen bronchitis and asthma® Exposure to air pollutants also increases the risk of dying from diseases like stroke, heart diseases, lung cancer and chronic respiratory diseases. Children, the elderly and people with heart or respiratory illnesses are more likely to be affected by air pollution. Suspended particulates — PM10 and PM2.5 Suspended particulates are very small solid particles or liquid droplets in air. They include PM 10 and PM2.5. The diagram below shows some information about them. PM10 o Less than 10 pm in diameter (i.e. less than 1/8 the diameter of a hair) « Can get deep inside the lungs ‘ PM2.5 e Less than 2.5 pm in diameter Can enter the blood through the air sacs and cause more Serious health problems } The World Health Organization® (WHO) has set a safety limit for PM2.5. In 2020, the level of PM2.5 in Hong Kong was 1.5 to 2.4 times higher than the limit. RE RNR RR LL RE IR RR RR RRR RR ra dizziness Sift asthma BM chronic respiratory disease 1&4 MFIR ZMH&K World Health Organization tt 53 4 BE 4  Air Quality Health Index (AQHI) If we can reduce the time staying outdoors when the air quality is bad, we can reduce the health risks caused by air pollution. But how do we know whether the air quality is good or not? We can check the Air Quality Health Index” (AQHI). The AQHI tells the public the possible health risks caused by air pollutants and help them take precautionary measures. The AQHIs are on a scale of 1 to 10 and 10+, and are grouped into five health risk categories. The table below shows the health advice in respect of individual categories. Health risk i gi BE won| OBE | G00 | me | ooo | mm. AAR a MODERATE A 5 A BE y SERIOUS Health No action is No action is No action is Reduce Reduce advice to needed needed needed outdoor outdoor the general activities activities public and the time and the time of staying of staying outdoors outdoors to the minimum Health No action is Individuals Reduce Reduce Avoid outdoor advice to needed who are outdoor outdoor activities people with experiencing activities activities existing symptoms and the time and the time heart or are advised of staying of staying respiratory to consider | outdoors outdoors to illnesses reducing | the minimum outdoor | activities EEE EEE EEE Lad PR TL LT EE A ARPA Lp EE EE EE EEA A EE LEE EAE Ad PPE LE EE EE PT Il EE 78 Air Quality Health Index ZRH FZ iE RIEH  AQHIs are calculated based on the amounts of certain air pollutants and local health statistics. The amounts of air pollutants are measured at air quality monitoring stations” in different districts. |. i8 k Fig 7.37 Air quality monitoring station in Central © After-class activity (5 Find the air quality monitoring station closest to your school. Check and record the AQHI of the station at the same time every day for one week. Discuss with your classmates about the air quality of your school and what health advices should be given to the students in your school. “Did you know? (» ) End of leaded petrol Lead™ was first added to petrol* in 1922 to make the engines of motor cars work better. However, lead is released into the atmosphere when the petrol burns in motor cars, causing air pollution. Breathing in lead may affect the development of the brain, especially in children. Due to the harmful effects of lead, many places started to ban the use of leaded petrol* in the 1980s. In 2021, as Algeria™ stopped the sale of leaded petrol, the use of leaded petrol ended globally. enn I III III emmy ee ee EE EE EE EE FP EF RE REEL EE EE EE A A EE EE I SE air quality monitoring station ZRH FZERIYE lead $i petrol J leaded petrol 28a) Algeria FoF KF 55 79  Q 4 Activity 7.4 Clean air for Hong Kong Read the article below and answer the questions. To improve the air quality in Hong Kong, the government released the Clean Air Plan for Hong Kong 2035" in 2021. The major goal of the plan is that the air quality in Hong Kong fully meets the ultimate targets under the guidelines of the World Health Organization. Here are some of the measures under the plan: Study the n0ossib lity ty ASof - Hydrogen § tuay the possibl % using hy rdrogen fuel”. Promote the use of (Hydrogen produces water only when it is burnt. Itis a clean fuel. ) & NE ae Sa “ a vy » eB Sein \vaSr 4 a Ade. } Fat ff Pe v 10C " - 2 i. Fe b : |. Cad - a5 17179. ) 118 18} 3 re iY JCL UY CAILIVJIUVA] A. ~ ] hee ha) : 4 4 CRS 3] § VORA ke Cain A 5 Ted +5 oa / / 111 : aff TATOEC =C TS WITH ooo LY YY LLL Fear poll lustants in rea EAR ¢ Il PEPLINAV Y)S LC A By a # k | eis oY A ; - AL sd a Ca Jv, 5 2 4 SEB WY 1 How can the use of hydrogen fuel help improve air quality? 2 ag ONE action the government can take to promote the use of electric cars. Stations. [Provide subsidies|0 3 Suggest ONE action individuals can do to help improve the air quality in Hong Kong. sr by bicycle inst se public Transport instead gfdriviey/ Trowel on F507 soy cor for short JOU neys. E OI NOs s eases stat r ists tsetse setts tos tossssetsaosoteteciorovisesatesnecvesessiataeessrslasiessinesssitienseecenisscaiestetiustodsisssinvansatuata tosses ae dsesesnisnvessvitsssiinntnpnne ERBARIO Rr PEI Rae RR CARER I EAU ROR U RIERA 80 Clean Air Pla n for Ho ng Ko ng 20 35 & # 5 1 2 2EEE 20 35 hydrogen fuel SURA%  Air quality os hy RU AEE R NTPoet Ai A Sey SANIT” iSectionlsummarya737 1 Sulphur dioxide, nitrogen oxides, ozone, carbon monoxide and suspended particulates are some of the major air pollutants. They can cause various health problems. The AQHI tells the public the possible health risks caused by air pollutants and help them take precautionary measures. ISectionlexerciseR77 Questions 1 to 3: Write “I” for a true statement and ‘F’ for a false statement in the boxes provided. 1 Air pollutants affect our breathing system only. &p. 77 2 The higher the AQH], the better the air quality. 3 People are advised to reduce the time of staying outdoors when the AQHI is high. ¢p./8 4 The table below shows the annual average levels of nitrogen dioxide” (one of the nitrogen oxides) recorded at two air quality monitoring stations in Hong Kong in 2021. The guideline value set by the World Health Organization (WHO) is 10 ng/m”. Air quality monitoring station Causeway Bay (Source: Website of Environmental Protection Department — Air Quality Health Index — Air Quality in Hong Kong 2021 Statistical Summary) a By how many times does the level of nitrogen dioxide at Causeway Bay (exceed|the guideline value set by the WHO? Show Yo working. (2 marks) U0. 10 24 Ufimes b Explain why the annual average level of nitrogen dioxide recorded at Causeway Bay was higher than that at Tap Mun. (2 marks) Cason B « [51h 7 iat ACA il T [Tun Ae AN Ho ube PE I TT I I TTT TTT ITT TI IMM TM mM IMM mM mM MM Mm mT Im IOI SY or eee EEE PP EEE EE EEE EEE EEE Ell hid ail dd dd hd hb EE dd LL pyEL EE EE El Le tp gps sranan sevbgdavay nitrogen dioxide —&AL& 81  1 nitrogen & p. 2 28 gas exchange SHH p- 40 2 oxygen & p.2 @29 stoma (pl. stomata) FFL p- 44 3 carbon dioxide —% {kik p- 2 4 noble gas RHE p- 2 30 inhaled air WAM B.3 S hiydropencabionste indicator 31 exhaled air IFH!% 5 p. 50 Aik RB i TR p. 4 6 Rite walt Tie b. 4 32 breathing system FFI 2%: p. 54 7 burning splint #8AI AAR p-5 35 rex 24 p- 3 8 glowing splint HA #RMEHI AME 2 b% Drenchiole SLY p. 54 9 cobalt chloride paper Fit &imlAK p-8 35 bronchus (pl. bronchi) XA% p- 54 36 diaphragm #iJiFfii p. 54 37 intercostal muscle ffl p. 54 10 photosynthesis Y&1EM p. 14 38 lung fii p. 54 11 chlorophyll ZX p- 14 39 nasal cavity £ Jp p. 54 12 glucose H#jHE p-15 40 nostril FFL p. 54 13 by-product BIEfF Pp: 15 41 rib BE p. 54 14 chemical change fb2&5{t p.15 42 trachea S/S p. 54 15 product AH p. 15 43 capillary i p. 55 16 reactant EY) p-15 44 rib cage EE p. 56 17 word equation XFRHER p. 16 @ 18 chemical equation {LZ fEX p. 16 19 starch E# p. 17 45 greenhouse effect IH ZEXLME p. 69 20 sodium hydrogencarbonate BEEN p. 21 46 globslwamiing SURE pA 21 destarching BE b. 23 47 climate change SRfEsE4L p. 72 22 control set-up ¥E#EE p. 24 23 soda lime MgAIK pP- 29 48 air pollutant Z=E5I5 44) p. 76 @ 24 food chain E¥)# p. 32 49 sulphur dioxide ZH AfbHi p. 76 @ 25 producer AE] p. 32 50 nitrogen oxides AHILY p. 76 @ 26 consumer HEH p. 32 51 ozone H& p. 76 52 carbon monoxide —%8ALHk p. 76 27 respiration FEES 0.38 53 suspended particulate $&FHT p- 76 32  Living things and air OE een EE is a mixture of gases, which include are |involved ed ini Isi one of the greenhouse gases AH : trap thermal energy and cause greenhouse effect maintain if enhanced, leads to balance of oxygen and carbon dioxide in Nature global warming in humans in plants Occurs in occurs through air sacs stomata 85  Sl — CT — ime —— Multiple-choice questions 1 A student added lime water to a test tube 4 Which of the following statements about of a colourless gas. The lime water turned respiration is / are correct? milky. If he adds hydrogencarbonate (1) Respiration does not occur in our cells indicator to another test tube of the same when we are at rest. gas, what colour will the indicator turn? (2) Chemical energy in food is converted A Blue B Red to other forms of energy during the C Purple D Yellow process. «7.1,p.9 (3) Oxygen is produced as a by-product in the process. @2 A food chain is shown below. A (2) only grass —» grasshopper — rat — snake B (3) only Ri | Which of the living things depends directly CD (1) (1) and and (2) only (3) only on light energy for a source of energy? «7.3, p. 38 A Grass B Grasshopper C Rat D Snake * 5 A plant was placed in a sealed glass 72.p. 32 container under a certain condition. After several hours, the percentage of oxygen in * 3 The photo below shows some plant cells. the air in the container increased, while the percentage of carbon dioxide decreased. Which of the following statements about the plant are correct? (1) Photosynthesis occurred in the plant. (2) Respiration did not occur in the plant. (3) The plant was placed under sunlight. A (1) and (2) only B (1)and (3) only C (2) and (3) only D (1), (2) and (3) ¢«/4,p.43 Which of the following about the cells is / are correct? 6 How do green plants help maintain the (1) They can absorb light energy. natural balance of gases in the atmosphere? (2) They can produce glucose under A They provide energy for animals. sunlight. B They absorb carbon dioxide from the (3) They can break down food to release atmosphere. energy. ~ C They release water vapour to the A (2) only B (1) and (2) only atmosphere. C (1)and 3)only D (1), (2) and (3) D They absorb thermal energy from the &7.2,p. 14-15, 7.3, p. 38 atmosphere. «7.6, p. 67  Living things and alr © True-or-false questions Study each of the following statements. Write “T” for a true statement and ‘F’ for a false statement. 1 Carbon dioxide is used in fire extinguishers because it does not support burning. ¢7.1,p.10 «2 Light energy is converted to food during photosynthesis in green plants. €7.2,p. 15 © 3 A food chain shows the direction of energy transfer between living things. “72,p. 32 4 Green plants take in oxygen from the air at night. «7.4, 0p. 43 5 Tar in cigarette smoke causes addiction. ¢7.5 p. 63 6 Global warming is mainly caused by the large amounts of carbon dioxide produced by respiration in living things. ¢7.6,p.70 (® Structured question The diagram below shows a structure in the human body and a capillary near it. Gas exchange occurs in this structure. X capillary Y a i State where in the human body this structure can be found. (1 mark) ii Explain why gas exchange is essential for the survival of humans. (2 marks) Q@ iii Draw arrows on the diagram to show the movement of oxygen and carbon dioxide between the air in the above structure and the blood in the capillary. (2 marks) Q@ iv Describe the differences in the contents of oxygen and carbon dioxide in the blood at locations X and Y. (2 marks) @b During an asthma attack, the trachea constricts. Describe how this affects the gas exchange occurring in the above structure. (2 marks) €¢ 7.5, p. 54-58 85  solution | Self-checking skill test Section A Interpreting data Designing a fair test 1 A student tested two jars of gases with a 3 To study whether light i$ necessary for glowing splint and both caused the glowing photosynthesis, he should compare the splint to go out. What can you tell from the results of result? A Wand. B Xand. A They are the same gas. C XandZ. D Y andZ. B One of them is oxygen. «7.2, p. 23 C One of them is carbon dioxide. D They do not support burning. Predicting results ¥ 4 He carried out iodine test on the leaf. Which of the following shows the possible results «7.1,p.9 of the iodine test? Part Results Questions 2 to 4: To study factors needed for A W It turns blue-black. photosynthesis, Alan carried out an experiment B X [t remains brown. using a destarched plant with variegated C Y It remains brown. leaves. He covered part of a leaf and put the D Z It turns blue-black. plant under sunlight for two hours. |] the part ©2722. p: 28 covered by aluminium W Describing observations foil 5 Which of the following is an observation X when a water plant is put under sunlight? A Photosynthesis occurs. B Carbon dioxide is used. C Glucose is formed. D Gas bubbles are formed. I] Designing a fair test ss ar y «7.2, p. 21 2 To st ud y wh et he r ch lo ro ph yl l is ne ce for ph ot os yn th es is , he sh ou ld co mp ar e th e identifying variables results of 6 In an experiment to compare the amounts A WandX. of energy released when two kinds of B Xand. food are burnt, wh ic h of the fo ll ow in g is a C XandZ. controlled variable? D YandZ A The a m o u n t of e n e r g y r e l e a s e d [] B The t y p e of f o o d u s e d C The mas s o f f o o d u s e d «7.2, 0 27 o f c a r b o n d i o x i d e p r o d u c e d D The amo u n t [| «7.3, p. 36  Setting up a control Understanding scientific terms 7 In an experiment to study the change in 8 Carbon dioxide makes up about 96.5% of the level of carbon dioxide caused by a Venus’s” atmosphere. A student states that grasshopper in a test tube, which of the the greenhouse effect on Venus is stronger following is a control set-up? than that on Earth. This is a(n) A A test tube with two grasshoppers A conclusion. B A test tube without any grasshopper B evidence. C A test tube with a grasshopper, covered C inference. with aluminium foil D observation. D A test tube with a grasshopper and a [] bag of soda lime [| €7.6,p.70 «7.5 p.47 Section B 9 Sofia used the set-ups on the right to study the hydrogencarbonate effect of light on the carbon dioxide content in water plant ~~ 'ndicator beakers with water plants. The set-ups (X and Y) were left in sunlight for two hours. Setting up a control a Explain which set-up (X or Y) is the control set-up for the experiment. (2 marks) Predicting results b Predict the colour of the hydrogencarbonate indicator in set-ups X and Y at the end of the experiment. Explain your answer. (4 marks)  Answers ? p.23 We can pick a leaf from the plant and carry out iodine test. The leaf should remain brown in the iodine test. p. 49 To eliminate the changes in the set-ups caused by changes in environmental factors, such as air temperature and pressure. QuickIcheck; p-59 1+ 2 TF Skill practice 7.1 (p. 26) B 88