A new government study suggests U.S. teen smoking rates reached an all-time low this year.  一项新的政府研究表明，今年美国青少年吸烟率达到历史最低点。  The study was a survey of American youth carried out by the U.S. Centers for Disease Control and Prevention (CDC).  该研究是美国疾病控制与预防中心（CDC）对美国青少年进行的一项调查。  The survey involved middle school students – which includes grades six through eight – and high school students in grades nine through 12. Nearly 30,000 students from 283 U.S. schools took part in the effort, which was carried out from January to May.  这项调查涉及中学生（包括 6 至 8 年级）和 9 至 12 年级的高中生。这项调查于 1 月至 5 月进行，共有来自 283 所美国学校的近 3 万名学生参与。  An estimated 33 percent of youth took part in the voluntary survey.  据估计，有 33% 的年轻人参加了这项自愿调查。  The study showed a 20 percent drop in the number of middle and high school students who said they recently used at least one tobacco product. These include cigarettes, electronic cigarettes, nicotine patches and hookahs.  研究显示，表示最近至少使用过一种烟草产品的初中生和高中生人数下降了 20%。其中包括香烟、电子烟、尼古丁贴片和水烟袋。  That number decreased from 2.8 million last year to 2.25 million this year. The result suggested the change was the lowest usage rate of those products since the CDC survey began in 1999.  这一数字从去年的 280 万减少到今年的 225 万。结果表明，这是自 1999 年 CDC 调查开始以来这些产品的最低使用率。  The Associated Press (AP) reports the drop is largely explained by another recent government survey showing e-cigarette use among U.S. youth in 2024 fell to its lowest level in 10 years.  美联社 (AP) 报道称，这一下降的主要原因是政府最近的另一项调查显示，到 2024 年，美国青少年的电子烟使用量将降至 10 年来的最低水平。  The youth e-cigarette rate fell to under six percent this year, a drop of 7.7 percent over last year. That was the lowest rate at any time during the past 10 years. Government records show e-cigarettes are the most commonly used tobacco products among teens. The second most common is the nicotine patch.  今年青少年电子烟使用率降至6%以下，比去年下降7.7%。这是过去十年来最低的比率。政府记录显示，电子烟是青少年最常用的烟草产品。第二个最常见的是尼古丁贴片。  In 1999, nearly 30 percent of American high school students smoked. In 2024, it was just 1.7 percent. Currently, the share of middle school students who smoke is also at its lowest rate. Recent use of hookahs also dropped, from 1.1 to 0.7 percent.  1999年，近30%的美国高中生吸烟。2024 年，这一比例仅为 1.7%。目前，中学生吸烟比例也处于最低水平。最近水烟的使用率也下降了，从 1.1% 下降到 0.7%。  CDC officials said the decreases are linked to several measures. These include product cost increases, public health education campaigns, age restrictions and more aggressive enforcement actions against makers and sellers to children.  疾病预防控制中心官员表示，数量减少与多项措施有关。其中包括产品成本增加、公共卫生教育活动、年龄限制以及针对儿童制造商和销售商的更严厉的执法行动。  Among high school students, use of any tobacco product dropped from 13 to 10 percent in 2024 while e-cigarette use fell from 10 to eight percent. The survey showed there was no change reported for middle school students who generally vape or smoke less than older children.  到 2024 年，高中生中任何烟草产品的使用率将从 13% 下降至 10%，而电子烟的使用率将从 10% 下降至 8%。调查显示，与年龄较大的孩子相比，