Question: I received a letter claiming to be from the U.S. Census Bureau notifying me that my participation in an “important survey … is essential.” It says a field representative will contact me for an interview. I am leery of unsolicited requests for personal information about my spending, family income, housing, etc. The letter looks authentic, but I’ve been warned that scammers are clever and can dupe citizens into divulging personal information that can be used against them. Can I choose to ignore this letter and decline to be interviewed?

Answer: The U.S. Census Bureau conducts dozens of demographic and economic surveys, some of which require the recipient’s participation under federal law and some of which are voluntary. The agency’s website, census.gov, lists the surveys it conducts, whether participation is required and how to verify whether any purported communication from the agency is genuine. Click on “Surveys & Programs” at the top of the Census home page for links to this information.

In a follow-up email, you provided the name of the survey mentioned in your letter: the Consumer Expenditure Survey, which collects data needed to calculate the Consumer Price Index, or CPI, the nation’s most widely used measure of inflation. Participation is voluntary, the website says. Households are chosen at random, and responses are confidential, used to produce statistical summaries that cannot identify anyone. The Census Bureau conducts this survey for the Bureau of Labor Statistics.

“This survey measures how people in the United States spend their money on items such as housing, food, education, transportation, and health care. … Participation is essential in order for the survey to provide a complete and accurate picture of how Americans spend their money. Knowing what goods and services consumers are buying and how much they are spending is critical information in determining the strength of our nation’s economy and the direction in which it is moving,” the website says.

Among many other uses, the CPI is the basis of cost-of-living adjustments for millions of American workers and retirees, and is used to adjust income-­eligibility levels for various government assistance. Read about this survey at census.gov/programs-surveys/ce.html, including how to verify any further contact from the Census Bureau.

Q: When is drug take-back day in Honolulu? I have expired asthma inhalers that no one will take back. The mail recycle serv­ice won’t take them, CVS won’t, Kaiser won’t. Is there any other way to dispose of them?

A: “Regular inhalers (2.5g or 0.41 oz) containing Albuterol Sulfate or Primatene MIST, for example, can be safely disposed with the regular trash,” Ian Scheuring, a spokesperson for the Honolulu mayor’s office, said in an email, conveying information from the city’s Department of Environmental Services.

As for your first question, the National Take-Back Initiative is Saturday from 10 a.m. to 2 p.m., and will collect expired or unwanted medication at nine sites on Oahu, Maui, Kauai and Hawaii island, according to the state Department of the Attorney General. See the flyer at ag.hawaii.gov for locations, which we also printed in Kokua Line on April 16.

Asthma inhalers will be accepted, Toni Schwartz, an AG spokesperson, said in an email.

NTBIs “are conducted twice a year and are free and anonymous services to the public — no questions asked. Tablets, capsules, liquids, and other forms of medication will be accepted. Everything can be kept in its original container. No labels need to be removed. Vaping devices will also be accepted, but batteries must be removed. New or used syringes will not be accepted,” according to the Attorney General’s Office’s news release.

In addition to these semiannual events, there are year-round medication drop-off boxes on Oahu, including at some retail pharmacies. Follow the links at dea.gov to search for the nearest one. But as you noted, and Scheuring confirmed, they don’t accept inhalers.

Write to Kokua Line at Honolulu Star-Advertiser, 500 Ala Moana Blvd., Suite 7-500, Honolulu, HI 96813; call 808-529-4773; or email kokualine@staradvertiser.com.